Serial communication network with a plurality of branches

Abstract

The present disclosure relates to a serial communication network (300) including: a plurality of branches (302), wherein each branch (302) includes a plurality of network nodes (304) connected to one another in a daisy chain configuration and configured to communicate with one another according to a wired communication protocol for serial communication, wherein the plurality of network nodes (304) in the branch (302) are connected according to a linear daisy chain topology and are configured for bidirectional communication, or wherein the plurality of network nodes (304) in the branch (302) are connected according to a loopback daisy chain topology and are configured for unidirectional communication; and a master control unit (310) common to the plurality of branches (302) and communicatively coupled with at least one network node (304, 306) of each branch (302) of the plurality of branches (302), wherein the network nodes (304) of at least one branch (302) are configured to support a plurality of physical modes for communication according to the wired communication protocol for serial communication.

Description

SERIAL COMMUNICATION NETWORK WITH A PLURALITY OF BRANCHESTechnical Field

[0001] The present disclosure relates generally to a serial communication network for wired communication including a plurality of branches each having a plurality of network nodes, with at least one node of each branch communicatively coupled to a master control unit that is common to the plurality of branches.Background

[0002] In general, many applications are based on the interplay of interconnected devices that act in concert to provide a certain functionality. An example of such a system are the so-called “smart surfaces”, a new type of human machine interface (HMI) that find applications in particular in the automotive context and industrial context. In a “smart surface” hundreds of light emitting diodes (LEDs) are controlled to dynamically and adaptively show information to a user, and sensors and actuators allow capturing inputs and commands from the user. In a system including many interconnected devices, communication protocols may regulate the data transfer among devices, thus ensuring a reliable communication and avoiding potential conflicts. In particular, in the context of systems including sensors, actuators, light emitting devices, etc. the data transfer among devices may occur via a wired connection (e.g., via a single-wire or via a plurality of wires), so that the connected devices may communicate according to a wired communication protocol that defines the rules for transmitting data. Improvements in architectures and communication strategies for wired-based communication may thus be of particular relevance for the further advancement of several technologies.Brief Description of the Drawings

[0003] In the drawings, like reference characters generally refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention. In the following description, various aspects of the invention are described with reference to the following drawings, in which:FIG.1A and FIG. IB show a system having a daisy chain network topology, in a schematic representation according to various aspects;FIG.2A shows a network node, in a schematic representation according to various aspects;FIG.2B shows an exemplary configuration of the network node, in a schematic representation according to various aspects;FIG.2C shows an exemplary configuration of the input / output ports of the network node, in a schematic representation according to various aspects;FIG.2D shows an exemplary configuration of electrically conductive lines connected with the network node, in a schematic representation according to various aspects;FIG.3A shows a serial communication network for wired communication including a plurality of branches, in a schematic representation according to various aspects;FIG.3B shows a master control unit of the serial communication network, in a schematic representation according to various aspects;FIG.3C shows a local master node for use in the serial communication network, in a schematic representation according to various aspects;FIG.3D shows a bridge node for use in the serial communication network, in a schematic representation according to various aspects;FIG.4A shows a schematic message flow diagram associated with a branch including a local master node, according to various aspects;FIG.4B shows a schematic message flow diagram associated with a branch including a bridge node, according to various aspects;FIG.5 A to FIG.5D show exemplary configurations of a branch for use in the serial communication network, in a schematic representation according to various aspects; andFIG.6A to FIG.6C show exemplary configurations of a serial communication network, in a schematic representation according to various aspects.Description

[0004] The following detailed description refers to the accompanying drawings that show, by way of illustration, specific details and aspects in which the invention may be practiced. These aspects are described in sufficient detail to enable those skilled in the art to practice the invention. Other aspects may be utilized and structural, logical, and electrical changes may be made without departing from the scope of the invention. The various aspects are not necessarily mutually exclusive, as some aspects may be combined with one or more other aspects to form new aspects. Various aspects are described in connection with methods and various aspects are described in connection with devices (e.g., a serial communication network, a network node, acommunication circuitry). However, it is understood that aspects described in connection with methods may similarly apply to the devices, and vice versa.

[0005] In general, networks of interconnected devices that communicate with one another via a wired connection and according to a wired communication protocol play an important role in a variety of applications, such as in lighting systems, sensor systems, and the like. For example, emerging lighting applications in automotive settings see the need of a growing number of interconnected and individually controllable light sources. The light sources should be controlled with low latency and to a high degree of precision throughout a wide range of operating conditions (especially temperature leads to visible changes of the displayed colors). Further applications such as “smart surfaces” require the combination of many LEDs (several hundreds) and sensor elements and / or actuator elements for the human-machine interface part. In these applications, data are regularly sent and retrieved from both the LEDs and the other nodes to provide a good user experience.

[0006] In this context, many communication protocols have been defined over the years to control the transfer of data among the networked devices. Broadly speaking, communication protocols may be divided in two main categories, parallel or serial. A parallel interface allows transferring multiple bits in parallel, whereas serial interfaces operate at a lower data rate (e.g., transferring a single bit at a time). However, with respect to parallel architectures, serial communication for a wired network may be implemented via a simpler setup (e.g., using a single wire, or in general less wires compared to parallel communication), and thus at a fraction of the cost. Serial communication may thus be of particular interest for wired network systems involving large numbers of interconnected devices.

[0007] Various options exist for serial network topologies, illustratively for the physical and / or logical arrangement of the nodes forming the communication network. The network topology may describe the path or paths available for a signal to travel through the network of interconnected nodes. In this context, the term “network node” may describe an electronic device that is part of the network. A “network node” may thus be an electronic device that includes communication circuitry to enable communication with other electronic devices (other nodes) that are part of the network. A “network node” may further include any suitable circuitry to implement additional functionalities, e.g. for carrying out a certain function or operation. As an example, considering a network of lighting fixtures, a network node may include light emitting circuitry configured to emit light. As another example, considering a network of sensor devices, a network node may include sensing circuitry configured to sense (or detect) a certain physical quantity such as temperature, light, mechanical vibrations, etc. A “network node” mayalso be referred to herein simply as “node”. It is understood that aspects described herein in relation to a “network node” may apply to the electronic device constituting that network node, and vice versa.

[0008] A simple network topology is the so-called “point-to-point topology”, in which exactly two nodes are directly connected (in other words linked) to one another. A further example may be the “star topology” in which each peripheral network node is connected to a central network node via an individual transmission line. A further example may be the “bus topology” in which the network nodes are connected to a common transmission line (illustratively, a common bus). In the “bus topology” several network nodes are connected at the same line providing a parallel connection of the network nodes. Further examples may be a “tree topology” or a “mesh topology”. So-called “hybrid topologies” that combine two or more types of topologies may also be provided.

[0009] In this context, an advantageous network topology for interconnecting electronic devices is the so-called “daisy chain topology” (see also FIG.1A and FIG. IB). In a daisy chain configuration the network nodes may be connected to form a series of nodes, in which each network node may be connected via a point-to-point connection with one or two further network nodes, illustratively a preceding node and / or a subsequent node in the chain of serially connected nodes.

[0010] A “daisy chain topology” may be “linear”, such that a first node is connected to a second node, the second node is further connected to a third node, the third node is further connected to a fourth node, etc. until the final node of the series is reached. The “linear configuration” may thus be a bidirectional network configuration in which each network node is connected to the next in the series (illustratively, in a line, or chain), and the communication runs through the series of connected nodes and then returns along the same path. In this configuration the first node and the last node are not directly connected.

[0011] As another example a “daisy chain topology” may have a “ring configuration”, such that a first node is connected to a second node, the second node is further connected to a third node, the third node is further connected to a fourth node, etc. and the final node of the series is connected back to the first node. The “ring configuration” may thus define a loop-back network, in which the network nodes are connected in series, and the last node is connected back to the first node, so that communication runs through the sequence of nodes in one direction and then loops back to the first node. In the ring topology, every network node may thus be connected to two other nodes, with the first node and the last node being connected to one another.

[0012] A “daisy chain topology” may enable a cost-effective and scalable architecture for providing a network configured according to serial communication. In particular, a “daisy chain topology” may be realized with a reduced number of terminals and connection lines compared to other configurations, thus providing a cost- and resource-efficient implementation. In the present disclosure references to a “daisy chain” may apply in a corresponding manner to a linear chain topology and to a ring chain topology, as appropriate from the context.

[0013] Therefore, wired networks having a daisy chain topology and based on serial communication are attractive for applications in which space and costs considerations may play an important role. In this framework, improved communication strategies for such type of networks may lead to a more cost- and resource-efficient operation, thus facilitating the integration of such systems in a variety of application scenarios.

[0014] In general, many communication protocols exist for governing wired-based serial communication. As a trait common to many communication protocols, wired-based serial communication may involve one network node acting as “primary node” and one or more other network nodes acting as “secondary nodes”.

[0015] In this context, the term “primary” may be used to describe the network node (illustratively, the corresponding electronic device) configured to control the operation of the other network nodes. The “primary node” may thus be configured to govern the transmission and the reception of data in the network, e.g. a “primary node” may be configured to transmit data to the one or more other “secondary nodes” and may be configured to request the transmission of data from the one or more other “secondary nodes”. A “primary node” may be understood as a device configured to instruct the operation of the one or more “secondary nodes” (e.g., providing instructions prompting the execution of one or more operations). A “primary node” may also be referred to herein as “master node”, “controller node”, “leader node”, or “host node”. In some aspects, a “primary node” may also be referred to herein as electronic control unit (ECU). As an example, a “primary node” may include a microcontroller or any other suitable control circuitry (e.g., a field programmable gate array, FPGA, an application specific integrated circuit, ASIC, etc.) to control the other nodes, e.g., to transmit instructions to the other nodes.

[0016] The term “secondary” may be used to describe a network node configured to be instructed by another network node, illustratively by the “primary node”. A “secondary node” may be a network node configured to receive instructions and to respond to the received instructions (e.g., without performing any active data transmission in absence of a prompt from the primary node). In some aspects, a “secondary node” may be configured to transmit data(e.g., various types of information), e.g. upon request from the primary node. A “secondary node” may also be referred to herein as “slave node”, “peripheral node”, “follower node”, or “responder node”.

[0017] In general, a wired communication protocol for serial communication may define a set of rules for controlling the data transfer among the network nodes. A wired communication protocol for serial communication may thus define the types of commands that may be sent / received, the types of responses to the different commands, the timing of the data transfer (e.g., synchronous or asynchronous), the layers for the communication, the type of coding for the data transfer, and the like. The type of node-to-node connection and the communication circuitry of a node may be adapted depending on the communication protocol according to which the nodes are configured, as in general known in the art.

[0018] Examples of communication protocols for wired-based serial communication may include the Inter-Integrated Circuit bus (I2C) protocol (e.g., according to I2C-bus specification and user manual Rev. 7.0 of 1 October 2021), the Serial Peripheral Interface (SPI) protocol, the single-wire (1-wire, or one-wire) protocol, the Controller Area Network (CAN) protocol, the Ethernet protocol, and / or the microwire protocol.

[0019] For example, there are a series of known LED drivers using a variety of bus systems (primarily XX-over-CAN-physical), which however only support a limited number of nodes (e.g., 100 to 200). Other exemplary LED drivers may be arranged in a serial chain and communicate via a unidirectional SPI-like bus. The nodes form a structure analogous to a shift register where data packets are pushed in until all units have received their data. However, this protocol only allows a single function and does not feature any diagnostic modes. Another protocol is the ISELED protocol for a serial chain of nodes, which supports more nodes (-4000) but uses the same bus for all connections.

[0020] Recently, a further communication protocol has been defined for wired-based serial communication, the so-called Open System Protocol (OSP). OSP may be used in a variety of implementations and has broad applicability. In one common implementation, OSP may be utilized in the context of a single microprocessor (as “primary node”) and multiple smart light emitting diode (LED) devices (as “secondary nodes”). The OSP defines a system architecture, commands, and data structure tailored to devices interconnected according to daisy chain network topology, and may thus enable a robust and efficient data transfer in such type of networks.

[0021] Aspects of the present disclosure are related to a system architecture for a serial communication network for wired-based communication. In particular, the architectureproposed herein may include a plurality of daisy chain-connected network nodes that are organized in a plurality of independent branches coupled to a common master control unit. Illustratively, the network described herein may include a master control unit that is communicatively coupled with the one node (e.g., the primary node, or a bridge node) of each branch to centrally control the operation of the branches in the network.

[0022] A configuration with a plurality of independent branches provides an architecture that may be conveniently scaled up to include a large number of network nodes, e.g. up to one thousand nodes per branch. Having separate branches allows controlling the operation of the network with reduced latency compared to a scenario in which all the network nodes are connected in a single chain. Furthermore, the proposed architecture simplifies the setup and the installation, e.g. in terms of wiring, allowing a more localized disposition of the nodes without having to provide wiring that connect all the nodes in a single chain. In some aspects, the proposed architecture may support one thousand nodes in a branch, with low latency and individual addressability. Further, the proposed architecture enables ease-of-use, improved electromagnetic compatibility, and low integration efforts (e.g., for installation in a vehicle).

[0023] The present disclosure describes a system of many individually controllable and readable nodes (e.g., LEDs, sensor, and the like) for applications such as ambient illumination and / or human-machine interfaces in motor vehicles. The proposed system includes many nodes, which may be configured for bidirectional communication thus enabling a time- and resourceefficient transfer of information in the network. Furthermore, the network nodes may be equipped with diagnostic capabilities, thus allowing a prompt response in case of potential malfunctions.

[0024] In general, common architectures employ parallel communication buses, such as Controller Area Network (CAN), Controller Area Network Flexible Data-Rate (CAN-FD), and the like, etc. Such buses however cannot handle more than about 200 nodes. Standard protocols also bring about a significant overhead reducing the overall efficiency of the communication and increasing the latency. Simpler protocols are fast but work only unidirectional, lacking the required diagnostic capability. The present disclosure relates to an illumination system supporting up to 1000 nodes per branch, having fast update rates and offering full diagnostic capabilities.

[0025] According to various aspects, a serial communication network includes a plurality of branches, each branch including: a plurality of network nodes (e.g., including a primary node and a plurality of secondary nodes), wherein the plurality of network nodes are connected to one another in a daisy chain configuration, wherein the plurality of network nodes areconfigured to communicate with one another according to a wired communication protocol for serial communication, wherein the plurality of network nodes are connected according to a linear daisy chain topology and are configured for bidirectional communication, or wherein the plurality of network nodes are connected according to a loopback daisy chain topology and are configured for unidirectional communication; and a master control unit common to the plurality of branches and communicatively coupled with at least one network node (e.g., the primary node) of each branch of the plurality of branches.

[0026] In the proposed configuration, the master control unit and the network node of a branch may communicate with one another in a bidirectional fashion. Illustratively, the master control unit may transmit data to the network node, and the network node may transmit data to the master control unit. This configuration allows the master control unit to provide instructions for controlling the behavior of the network nodes in a branch, and further allows the master control unit to receive information on the network nodes of the branch. For example, the network node may transmit diagnostics information to the master control unit, e.g. representative of a temperature at the branch, of a voltage at the branch, of a malfunction in a node, etc. The master control unit may thus receive (updated) information on possible criticalities in a branch and take appropriate corrective actions, e.g. interrupting a voltage supply to that branch or to a node of the branch, sending an alert to a user, and the like.

[0027] In a preferred configuration, the network nodes of a branch (e.g., at least one branch, e.g. each branch) may be configured to support a plurality of physical modes for wired communication. In this regard, the term “physical mode” may be used herein as commonly understood in the art to describe the physical way in which a signal is transmitted from one network node to another network node. Illustratively, a “physical mode” may describe how the network node makes use of the physical layer for communicating with another network node. A “physical mode” may thus include transmission parameters related to the physical transmission of the signal. A configuration in which a network node is configured to enable multiple physical modes enhances the flexibility of the arrangement, e.g. to tailor the specific physical mode used at specific locations of the chain taking into account system considerations (e.g., a particular location in a host device in which a certain wiring or certain voltage values is / are more appropriate, as an example).

[0028] In a preferred configuration, the network nodes of the network may be configured to communicate with one another according to the Open System Protocol (e.g., according to OSIRE® E3731i - Open System Protocol 1.0, Application Note AN162 of 2023-07-06). The OSP protocol may be particularly suitable for managing communication in daisy chainnetworks, e.g. in daisy chains of light emitting elements, and may thus constitute the most relevant use case for the proposed readout strategy. The use of the OSP protocol facilitates providing complex illumination systems, e.g. in a vehicle.

[0029] Thus, in the present disclosure particular reference may be made to a serial communication network in which the network nodes are configured to communicate with one another according to the Open System Protocol. In the following, use may be made of concepts and terminology that pertain to the OSP context. It is however understood that the aspects described herein may be broadly applied to other types of wired communication protocols for serial communication. Furthermore, some examples may refer to specific wired communication protocols (e.g., to a specific version or release of a wired communication protocol), but it is understood that the examples provided herein may be similarly applied to various other wired communication protocols or other versions / releases of the wired communication protocols, both existing and not yet formulated.

[0030] Further, in a preferred configuration the network nodes of the serial communication network (e.g., of at least one branch, e.g. of each branch) may include one or more light emitting elements (e.g., one or more light emitting diodes, LEDs). Illustratively, the proposed architecture may be of particular interest for efficiently operating nodes in a daisy chain of RGB LEDs. This arrangement may be provided, for example, for a “smart surface” (e.g., in a vehicle). It is however understood that the configuration proposed herein may be applied to any suitable type of network node, e.g. to a network node configured to implement any suitable functionality.

[0031] In a preferred configuration, a multi-branch network configured as described herein may be for use in a vehicle, e.g. to provide ambient illumination in the interior of the vehicle, to provide illumination at the exterior of the vehicle, to provide a smart surface, and the like. The vehicle may be a motor vehicle, in particular a car, or another type of motor vehicle such as a motorcycle, a truck, a van, and the like. In some aspects, a vehicle may include one or more multi-branch networks configured as described herein. The proposed architecture enables individually controlling a large number of nodes, thus enhancing the flexibility of the system, which may be of particular relevance for ambient illumination in motor vehicles. For example, a high number of individually addressable LED nodes with low latency times enable smooth animations. As another example fast feedback from sensors or in case of errors through bidirectional communication ensure a rapid response.

[0032] It is however understood that the multi-branch network proposed herein may also be for use in other types of applications. As another example, the multi-branch network may be foruse in a (smart) home, e.g. to provide ambient illumination in a room or in the building, or to provide a distributed monitoring of the environment (e.g., of the temperature) and an adaptation of the illumination based on the environment.

[0033] FIG.1A and FIG.1B show a network 100 including a plurality of network nodes arranged in a daisy chain topology, in a schematic representation according to various aspects. In general, the network 100 may include a plurality of network nodes 102 disposed according to a daisy chain configuration. Illustratively, the network nodes 102 may be connected to form a series of network nodes, such that each network node 102 is connected with one or two other network nodes 102, and a data transfer within the network may include a propagation of the data from one network node 102 to the next node in the chain. In this regard, the network 100 may have a “linear” daisy chain topology, as shown for the configuration 100a in FIG.1 A, or a “ring” daisy chain topology, as shown for the configuration 100b in FIG. IB.

[0034] According to the “linear” daisy chain topology, a first node 104 may be connected to a second node 106a, the second node 106a may be further connected to a third node 106b, etc. until a last node 106d is reached. As mentioned above, in this configuration the last node 106d and the first node 104 are not directly connected, and the communication between nodes may be bidirectional, thus allowing a flow of information from the first node 104 towards the last node 106d, and vice versa.

[0035] According to the “ring” daisy chain topology, the first node 104 may be connected to the second node 106a, the second node 106a may be further connected to the third node 106b, etc. until the last node 106d is reached. As mentioned above, in this configuration the last node 106d and the first node 104 may be directly connected, providing a loop-back arrangement. In this configuration, the communication between nodes may be unidirectional, thus allowing a flow of information from the first node 104 towards the last node 106d, and then a loop-back of the information from the last node 106d to the first node 104.

[0036] A network with a linear daisy chain topology, and a serial communication network with a ring daisy chain topology may be collectively referred to as network. The exemplary configurations in FIG.1A and FIG. IB show a network 100 with five nodes 102, but it is understood that the network 100 may include any suitable number of nodes.

[0037] According to various aspects, the network nodes 102 may include a primary node 104 and one or more secondary nodes 106a-106d (illustratively, a master node 104 and one or more slave nodes 106a-106d), e.g. a plurality of secondary nodes 106a-106d. As mentioned, the primary node 104 may govern the communication within the network 100. For example, the primary node 104 may include control circuitry 108 configured to control a communicationwithin the network 100, e.g. configured to control a data transfer over the daisy chain of network nodes 102. Illustratively, the control circuitry 108 may be configured to cause a transmission of messages along the chain of secondary nodes 106a-106d, and to prompt a response from one or more of the secondary nodes 106a-106d. The primary node 104 may further include communication circuitry 112 to send / receive data to / from the chain of secondary nodes 106a-106d. As an exemplary realization, the primary node 104 may be or include a microcontroller, e.g. a microcontroller unit (MCU). In some aspects, the primary node 104 may be a unique node within the network 100. In some aspects, the primary node 104 may be further connected to a backbone network.

[0038] In general, each network node 102 may have a corresponding address associated therewith. The “address” of a node 102 may be a unique identifier of that node 102, and may allow delivering messages to that node 102. Illustratively, a message propagating along the chain of nodes 102 may include an address field including the address of the node 102 to which the message is addressed. Upon receiving a message, a node 102 may compare the address field of the message with its own address, and either execute an instruction contained in the message if the message is addressed for that node 102, or further propagate the message along the chain if the message is addressed to another node 102.

[0039] According to various aspects, each network node 102 may be aware of its respective position within the sequence of network nodes 102. With reference to the secondary nodes 106a-106d, the secondary node 106a connected with the primary node 104 may be the initial node of the sequence of secondary nodes, the secondary node 106d may be the final node of the sequence of secondary nodes (illustratively, an end-of-line, EOL, node), and the other secondary nodes 106b, 106c may be intermediate nodes between the initial node and the final node. Each secondary node 106a-106d may be aware of where the node is located within the sequence, e.g. at position one, two, three, etc. until the final position.

[0040] According to various aspects, neighboring network nodes 102 may be connected to one another via a wired connection 110. In this regard, the term “neighboring” or “adjacent” may be used to describe network nodes 102 at consecutive positions within the sequence of network nodes 102, illustratively logically adjacent network nodes 102, without implying a spatial relationship between the network nodes 102. In this framework, considering a certain node 102 as reference point, the term “next” or “subsequent” may be used to describe a further node 102 that is adjacent to the reference node, and is positioned downstream along the chain with respect to a direction of the data transfer. Thus, a message may propagate from the reference node to the next node, and then to a further next node and so on. In a corresponding manner, the term“previous” or “preceding” may be used to describe a further node 102 that is adjacent to the reference node, and is positioned upstream along the chain with respect to a direction of the data transfer. Thus, a message may propagate from the preceding node to the reference node.

[0041] The wired connection 110 may include one or more wires that electrically conductively connect one network node 102 with the neighboring network node(s) 102. Illustratively, a wired connection 110 may include one or more electrically conductive lines (e.g., electrically conductive wires, or electrically conductive traces). The wired connection 110 may illustratively be a serial bus to which the network nodes 102 are connected forming a chain. The number of electrically conductive lines of a wired connection 110 may be adapted according to the communication protocol via which the network nodes 102 communicate. In a preferred configuration, a wired connection 110 between neighboring nodes 102 may include exactly two electrically conductive lines. A configuration with two electrically conductive lines may allow implementing the OSP protocol, and may thus be particularly suitable for data transfer in a daisy chain network 100. It is however understood that in general a wired connection 110 may include any suitable number of electrically conductive lines, e.g. one, two, three, four, etc. In some aspects, a wired connection 110 may include at maximum four electrically conductive lines.

[0042] According to various aspects, the network nodes 102 may be configured to communicate with one another according to a wired communication protocol for serial communication (also referred to herein as base communication protocol). Illustratively, the network nodes 102 may be configured to transfer data along the chain of nodes according to rules and parameters defined by the wired communication protocol.

[0043] As mentioned, in a preferred configuration the network nodes 102 may be configured to communicate with one another according to the Open System Protocol, as this particular protocol may enable a robust communication in daisy chain networks, in particular for daisy chains of light emitters. It is however understood that the aspects described herein may broadly apply to a configuration in which the network nodes 102 communicate according to another type of wired communication protocol for serial communication.

[0044] In general, the details of the Open System Protocol are known in the art. An abridged overview is provided herein to introduce aspects relevant for the present disclosure. The OSP protocol may include a layer architecture with five layers, namely an application software layer, an application specific protocol layer, a network layer, a data link layer (DLL), and a physical (PHY) layer. The network layer may define commands conventions for interpreting the data. The DLL may describe the frame format and the encoding ofmessages according to the OSP protocol. A message may also be referred to as “telegram”. The PHY layer may govern the actual transmission over the physical medium (illustratively, communication via the wired connection).

[0045] The OSP protocol may include a plurality of physical modes, illustratively a plurality of modes of communication, namely a low-voltage differential signaling mode (LVDS mode); an end of line (EOL) mode or microcontroller (MCU) mode; a unidirectional single-ended (USE) mode which may also be referred to as CAN mode (where CAN is an acronym for controller area network). Considering the configuration in which the network nodes communicate according to the OSP protocol, the aspects of the present disclosure may apply to each of the possible communication modes. In the OSP protocol, communication is message based, and a message may have a frame format. The frame may include different fields, namely a preamble, an address, a payload size indicator (PSI), a command, a payload, and a cyclic redundancy check (CRC). The fields of the frame may have different lengths (expressed in bits), and the message length may be variable (e.g., up to 12 bytes). For example, the preamble may be 4 bit long. The address may be 10 bit long and may indicate the address of the target node to which the message is addressed. The PSI may be 3 bit long and may indicate the length of the payload in bytes. The command may be 7 bit long, and commands may be device specific. The payload may have variable length in a range from 0 to 64 bit, as indicated by the PSI. The CRC may be 8 bit long and may include a checksum calculated over the full message excluding the CRC field. A message “field” may also be referred to herein as message “portion”.

[0046] According to the OSP protocol the primary node is able to identify the device type of each node in the chain. In this regard, each node may have a respective read-only identification code (e.g., 32 bit long). The read-only identification code may include information representing the node / device, such as device type (e.g., light emitting circuit, sensor, etc.), manufacturer, part identification, and part revision.

[0047] FIG.2A shows a network node 200 in a schematic representation, according to various aspects. Illustratively, FIG.2A shows an electronic device configured for use as network node in a serial communication network. The network node 200 may thus be a configuration of a network node 102 of the network 100 (e.g., a secondary node 106a-106d). It is understood that the representation of the network node 200 may be simplified for the purpose of illustration, and the network node 200 (electronic device) may include additional components with respect to those shown. An “electronic device” may also be referred to herein as electronic module.

[0048] In general, the network node 200 may include communication circuitry 202 configured to enable a communicative coupling of the network node 200 with a further electronic device (illustratively, with a further network node). The communication circuitry 202 may be configured to control a voltage level at the wired connection between the network node 200 and the further network node to encode data in the modulation of the voltage level. The communication circuitry 202 may include communication hardware 238 and a processor 240. The processor 240 may be configured to control the communication hardware 238 to implement the communication at the physical level, e.g. to control / define the voltage level at the wired connection. The processor 240 may be further configured to interpret (e.g., decode) messages received at the network node 200, and to generate corresponding response messages to be transmitted using the communication hardware 238. References herein to a configuration of the communication circuitry 202 of a network node 200 may correspondingly refer to a configuration of the communication hardware 238 (at a physical level) and / or processor 240 (at a logical level), as appropriate. As an exemplary realization the processor 240 may be a microprocessor. Illustratively, the communication circuitry 202 may be an integrated circuit (IC) configured to enable communication to / from the network node 200.

[0049] The communication circuitry 202 may be configured to receive, interpret, and send messages according to a wired communication protocol (e.g., the OSP protocol). In some aspects, the communication circuitry 202 may be configured to detect communication errors, e.g. to identify errors along the chain. For example, the communication circuitry 202 may be configured to carry out communication diagnostics, e.g. by interpreting a received message or a portion of the received message, to identify possible communication issues (e.g., incomplete messages, missing address, and the like).

[0050] In some aspects, a first voltage level at the wired connection (e.g., a high voltage level) may be associated with a logic “1”, and a second voltage level at the wired connection (e.g., a low voltage level) may be associated with a logic “0”. It is however understood that the definition of logic “1” and logic “0” and of the type of signal modulation associated thereto may be arbitrary (e.g., other examples of modulation may include the signal amplitude, the signal frequency, the signal period, etc.). A high voltage level may be understood as a signal having a voltage above a voltage threshold. A low voltage level may be understood as a signal having a voltage below a voltage threshold. Only as a numerical example, a high voltage level may be 1 V and a low voltage level may be 0 V. Considering a configuration according to the OSP protocol the network node 200 may support 3.3 V and 5 V logic levels.

[0051] As an exemplary realization, the communication circuitry 202 (as part of the communication hardware 238) may include one or more switch elements (e.g., one or more transistors) to selectively connect or disconnect an electrically conductive path between the wired connection and ground, and / or to selectively connect or disconnect an electrically conductive path between the wired connection and a supply voltage. The processor 240 may be configured to control the one or more switch elements to define the voltage level at the wired connection.

[0052] According to various aspects, the network node 200 may include a plurality of input / output ports 206, 208, and the communication circuitry 202 may be coupled with the input / output ports 206, 208. In operation, the network node 200 may receive data via a first input / output port 206, 208 and output data via a second input / output port 206, 208. The propagation direction of the data may vary depending on the configuration of the daisy chain network and depending on the node to which the data are addressed. Illustratively, each input / output port 206, 208 may be configured for coupling with a wired connection (e.g., with one or more electrically conductive lines), and the communication circuitry 202 may be coupled with the wired connection through the input / output port 206, 208. An exemplary configuration for the input / output ports 206, 208 will be described in FIG.2C.

[0053] The network node 200 may further include functional circuitry 204 configured to implement a primary function of the network node 200. Illustratively, the network node 200 may in general be designed to carry out a certain operation, and the communication circuitry 202 may allow interconnecting the network node 200 with other network nodes to exploit its operation in cooperation with the other devices. In some aspects, a network node 200 may also not include any functional circuitry 204 and just include communication circuitry 202 to enable propagating messages in the chain of nodes.

[0054] In some aspects, the communication circuitry 202 and the functional circuitry 204 may be integrated on the same substrate, e.g. the same printed circuit board. For example, a network node 200 may be a monolithic device in which the communication circuitry 202 and the functional circuitry 204 are integrated, e.g. within a housing.

[0055] The functional circuitry 204 may have any suitable configuration and include any suitable components depending on the intended use of the network node 200. In a preferred configuration, as shown in FIG.2B, a network node 200b may include (as functional circuitry 204b) light emitting circuitry, e.g. a driver circuit 210 and one or more light emitting elements 212. The driver circuit 210 may be configured to control a light emission by the one or more light emitting elements 212. The driver circuit 210 may be configuredto implement any suitable driving scheme, e.g. current dimming, pulse width modulation (PWM), PWM dimming, pulse duration modulation (PDM), and the like.

[0056] In principle, the light emitting elements 212 may be of any suitable type. Considering the context of integrated circuits, the light emitting elements may be or include light emitting diodes (LEDs), e.g. the one or more light emitting elements 212 may include at least one light emitting diode. As another example, the light emitting elements 212 may be or include laser diodes, e.g. edge emitting laser diodes or vertical cavity surface emitting laser diodes.

[0057] The light emitting elements 212 (e.g., the LEDs) may be configured to emit light having a predefined wavelength, for example in the visible range (e.g., from about 380 nm to about 700 nm), infrared and / or near-infrared range (e.g., in the range from about 700 nm to about 5000 nm), or ultraviolet range (e.g., from about 100 nm to about 400 nm). In some aspects, the light emitting elements 212 may be configured to emit light in different wavelength ranges. For example a first light emitting element 212 may be configured to emit light in a first wavelength range (e.g., a first color, for example blue), a second light emitting element 212 may be configured to emit light in a second wavelength range (e.g., a second color, for example red), and a third light emitting element 212 may be configured to emit light in a third wavelength range (e.g., a third color, for example green), etc.

[0058] It is understood that in other aspects an electronic device for use as a node in a daisy chain network may include a different type of functional circuitry 204. As another example, the network node 200 may include (as functional circuitry 204) sensing circuitry configured to sense a physical quantity, e.g. temperature, humidity, light, vibrations, force, touch, etc. In this configuration the functional circuitry 204 may further include a sensor controller to control the operation of the sensing circuitry, e.g. to prompt carrying out a sensing measurement, to collect data, and the like. For example, the sensing circuitry may include a transimpedance amplifier and an analog-to-digital converter to convert analog measurements into a digital representation. In some aspects, the sensing circuitry may include a buffer (e.g., a register) to temporarily store the sensor data until the sensor data are requested / retrieved, e.g. by the primary node or master control circuit of the network.

[0059] The functional circuitry 204 may be communicatively coupled with the communication circuitry 202. The communication circuitry 202 (e.g., the processor 240) may thus be configured to deliver instructions to the functional circuitry 204 (received from the primary node of the network) and / or to receive information from the functional circuitry 204. For example, the communication circuitry 202 may receive statusinformation from the functional circuitry 204, e.g. representative of operating parameters, of a current operation status (e.g., active, idle), the result of a sensing process, and the like.

[0060] According to various aspects, the network node 200 may further include a memory (not shown). The memory may be configured to store data and instructions for an operation of the network node 200. For example, the memory may be configured to store communication parameters for the communication circuitry 202 to carry out the communication via the wired connection. As another example, the memory may be configured to store instructions for operating the functional circuitry 204. As another example, the memory may be configured to store production related data, e.g. calibration data such as optical calibration data in case of a light emitting node. The data in the memory may be sent by the network node 200 upon request, e.g. upon receiving a corresponding query by the primary node or master control unit of the network.

[0061] According to various aspects, the network node 200 may further include diagnostics circuitry configured to sense one or more operating parameters of the network node 200 and determine the occurrence of a potentially faulty condition of the network node 200. For example, the diagnostic circuitry may be part of the integrated circuit 202. For example, the diagnostics circuitry may include a temperature sensor configured to sense a temperature of the network node 200 and generate an alert signal in case of over temperature, e.g. in case the sensed temperature is in a predefined alert range (e.g., in case the sensed temperature is greater than a predefined threshold temperature). As another example, the diagnostics circuitry may include a voltage sensor configured to sense a voltage at the network node 200 and generate an alert signal in case of over voltage, e.g. in case the sensed voltage is in a predefined alert range (e.g., in case the sensed voltage is greater than a predefined threshold voltage).

[0062] FIG.2C shows exemplary configurations for the input / output ports 206c, 208c of the network node 200. According to various aspects, the network node 200 may include two identical input / output ports 206c, 208c, each including two input / output pins 214, 216, 218, 220. This configuration may be provided for communication according to the OSP protocol, or other protocols that make use of input / output ports with two input / output pins. It is however understood that in other aspects the input / output ports 206, 208 of the network node 200 may have a different configuration depending on the specific communication protocol used.

[0063] Two configurations may be provided. A first configuration 200c- 1 may provide a symmetric alignment, in which a first input / output pin 214 of the first input / output port 206c may be coupled with a corresponding first input / output pin 218 of the secondinput / output port 208c, and a second input / output pin 216 of the first input / output port 206c may be coupled with a corresponding second input / output pin 220 of the second input / output port 208c. Considering the OSP protocol, the symmetric configuration may be provided, for example, when inter-node connectivity is realized via LVDS.

[0064] A second configuration 200c-2 may provide a crossed alignment, in which the first input / output pin 214 of the first input / output port 206c may be coupled with the second input / output pin 220 of the second input / output port 208c, and the second input / output pin 216 of the first input / output port 206c may be coupled with the first input / output pin 218 of the second input / output port 208c. Considering the OSP protocol, the symmetric configuration may be provided, for example, when inter-node connectivity is realized via USE mode (or CAN mode).

[0065] FIG.2D shows an exemplary configuration for connecting the network node 200d to electrically conductive lines 222, 224, 226, 228. As shown, the first input / output pin 214 of the first input / output port may be connected to a first electrically conductive line 222, the second input / output pin 216 of the first input / output port may be connected to a second electrically conductive line 224, the first input / output pin 218 of the second input / output port may be connected to a third electrically conductive line 226, and the second input / output pin 220 of the second input / output port may be connected to a fourth electrically conductive line 228.

[0066] The electrically conductive lines 222, 224, 226, 228 associated with each of the pins 214, 216, 218, 220 may be connected to a pull-up resistor or a pull-down resistor, such as depicted in 230, wherein the first transmission line 222 is connected to a pull-up resistor and the second transmission line 224 is connected to a pull-down resistor, and in 232 wherein the third transmission line 226 is connected to a pull-up resistor and the fourth transmission line 228 is connected to a pull-down resistor. Naturally, this configuration is given for demonstrative purposes, and the polarities of the pins and corresponding lines may be reversed as desired for a given implementation. The resistance of the various pull- up resistors and pull-down resistors depends at least on the type of signal encoding used, the magnitude of the supply voltage, and the range of voltage used for signal transmission. Only as a numerical example the pull-up resistors and pull-down resistors may each be approximately 10 kfl. The resistors may couple the electrically conductive lines 222, 224, 226, 228 with a supply voltage 234 (illustratively, with a supply terminal configured to be coupled with a supply source) and / or with ground 236 (illustratively, a ground terminal), thus enabling a modulation of the voltage level at the electrically conductive lines 222, 224, 226, 228.

[0067] As mentioned above, aspects of the present disclosure may be related to an architecture including a plurality of branches. In this regard, each branch may be generally configured as the network 100 in FIG. 1A or FIG. IB. Illustratively, each branch may be a sub-network of the architecture, e.g. dedicated to a specific function, or associated with a specific location in the host device, etc. The various sub-networks may be communicatively coupled with a master control unit that acts as a central point of command for the plurality of sub-networks, thus orchestrating the behavior of the branches and ensuring an efficient and structured operation.

[0068] The proposed architecture may include sub-networks having the same configuration, e.g. sub-networks all having a linear daisy-chain topology or loopback daisy chain topology. Alternatively, the proposed architecture may include sub-networks having different topologies, e.g. a sub-network may have a linear daisy-chain topology and another sub-network may have a loopback daisy chain topology. The flexibility of the architecture facilitates its integration in complex systems, e.g. in a vehicle.

[0069] The general aspects of the proposed architecture will be described in relation to FIG.3A to FIG.3D. Different scenarios for the transfer of data to and from a branch will be discussed in relation to FIG.4A and FIG.4B. Possible configurations of the individual branches will be discussed in relation to FIG.5A to FIG.6C.

[0070] FIG.3A shows a serial communication network 300 configured as proposed herein. The serial communication network 300 may include a plurality of branches 302, and a master control unit 310 common to the plurality of branches 302. In the exemplary configuration in FIG.3, the serial communication network 300 may include a first branch 302-1, a second branch 302-2, and an N-th branch 302-N. In general, the serial communication network 300 may include any suitable number of branches 302, e.g. two, three, four, five, ten, or more than ten. The serial communication network 300 may also be referred to herein simply as network 300. A branch (e.g., a branch 302) may also be referred to herein as sub-network or partial network.

[0071] The network 300 may be for use in any suitable host device, in which the various branches 302 are provided at different locations in the host device, or to carry out different functionalities in the host device. In a preferred configuration, the network 300 may be for use in a vehicle (e.g., a car), for example to provide ambient illumination, a smart surface, signaling functionalities, and the like. According to various aspects, a vehicle (e.g., a car) may include one or more networks 300. In this scenario, the master control unit 310 may be a central control unit of the vehicle, and the various branches 302 may be disposed in different parts of the vehicle, such as in a door, in the interior of the vehicle (e.g., for ambient illumination), in thedashboard, in the exterior part of the vehicle (e.g., for exterior signaling), and the like. It is understood that the use in a vehicle may be the most relevant use case for the proposed architecture, but the network 300 may in principle be integrated in other types of systems or devices.

[0072] The configuration of the branches 302 will be discussed in further detail in FIG.5A to FIG.6C. In brief, a branch 302 may include a plurality of network nodes 304. The network nodes 304 in the branch 302 are connected to one another in a daisy chain configuration, in other words in a daisy chain topology, e.g. a linear daisy chain configuration / topology (as in FIG.1A) or a loopback daisy chain configuration / topology (as in FIG. IB). In a simple configuration, all the branches 302 may have the same daisy chain topology, e.g. all the branches 302 may have a linear daisy chain topology or all the branches 302 may have a loopback daisy chain topology. In other aspects, to tailor the architecture to specific system conditions, the branches 302 may have different daisy chain topologies. In this other scenario, at least one branch 302 (e.g., the first branch 302-1, or a first plurality of branches) may have a linear daisy chain topology and at least one other branch 302 (e.g., the second branch 302-2, or a second plurality of branches) may have a loopback daisy chain topology.

[0073] The network nodes 304 of a branch 302 may include a network node 306 that interfaces the branch 302 with the master control unit 310, and a plurality of secondary nodes 308. Illustratively, the master control unit 310 is communicatively coupled with at least one network node 306 of each branch 302. In the present disclosure the network node in a branch 302 that is communicatively coupled with the master control unit 310 may be referred to as “interface node”, “coupled node”, or “input / output node”.

[0074] In the configuration in FIG.3 the interface node 306 with which the master control unit 310 is communicatively coupled is shown as the first node or initial node of the chain in a branch 302. It is however understood that in principle the interface node 306 may be disposed at any suitable location within the daisy chain. Various possible configurations of the interface node 306 may be provided, e.g. as local master node, or as bridge node, as will be discussed in further detail in relation to FIG.3C and FIG.3D.

[0075] In each branch 302, the network nodes 304 are configured to communicate with one another according to a wired communication protocol for serial communication. A branch 302 may thus include a wired connection 312 between the nodes 304. The wired connection 312 may include one or more electrically conductive lines, e.g. a plurality of electrically conductive lines, coupling two network nodes 304 with one another. For example the wired connection 312 may include exactly two electrically conductive lines. Each network node 304 may includecommunication circuitry 314 configured to carry out wired based communication via the wired connection 312 coupled to node 304, e.g. as discussed in relation to FIG.2D.

[0076] As mentioned, in a preferred configuration the network nodes 304 in a branch 302 may be configured to communicate with one another according to the OSP protocol, but the aspects discussed in relation to the network 300 may broadly apply to other wired communication protocols for serial communication. In the preferred configuration, the network nodes 304 in each branch 302 may thus be configured to communicate with one another according to the OSP protocol. In other possible configurations, network nodes 304 in different branches 302 may communicate according to different wired communication protocols for serial communication.

[0077] Further, in a preferred configuration at least one branch 302 may include network nodes 304 (e.g., secondary nodes 308) configured as the network node 200b in FIG.2B, e.g. the branch 302 may include nodes having a driver circuit and one or more light emitting elements, e.g. one or more LEDs. It is however understood that the aspects discussed in relation to the “network 300 may broadly apply to other types of nodes (e.g., sensors, actuators, and the like).

[0078] For example, at least one branch 302 (e.g., the first branch 302-1, or a first plurality of branches) may include as network nodes 304 (e.g., as secondary nodes 308) a plurality of light emitting nodes. Another branch 302 (e.g., the second branch 302-2, or a second plurality of branches) may include as network nodes 304 a plurality of sensor nodes. A further branch 302 (e.g., the N-th branch 302-N, o a third plurality of branches) may include as network nodes 304 a plurality of actuator nodes, etc. It is understood that also “mixed configurations” may be provided, in which a branch 302 includes network nodes of different types, illustratively network nodes configured to implement different functionalities. For example a branch 302 may include one or more light emitting nodes and one or more sensor nodes, or a branch 302 may include one or more sensor nodes and one or more actuator nodes, as another example.

[0079] The proposed architecture enables managing a large number of nodes 304 in each branch 302. The specific number of nodes 304 in a branch 302 may then be freely adapted depending on the system requirements. In general, a branch 302 may include a number of network nodes 304 in the range from 2 to 1000, e.g. a number of network nodes 304 in the range from 10 to 700, e.g. a number of network nodes 304 in the range from 50 to 500. In some aspects, a branch 302 may include more than 500 network nodes 304, e.g. more than700 network nodes 304, e.g. more than 900 network nodes 304, e.g. 1000 network nodes 304.

[0080] In the proposed architecture, the master control unit 310 may act as a central orchestrator for the operation of the branches 302, thus enabling a coordinated and efficient functioning of the network nodes 304 in each branch 302. The master control unit 310 may include processing circuitry configured to receive information (data) from the various branches 302, process the received information, and control accordingly the network nodes 304 of the branches 302. The master control unit 310 may also be referred to herein as master processor, central control unit, central processor, branch control unit (BCU), or simply as control circuit. Considering installation in a vehicle, the master control unit 310 may also be referred to as vehicle control unit.

[0081] In the proposed architecture there may be bidirectional communication between the master control unit 310 and each branch 302. Illustratively, the master control unit 310 and the respective interface node 306 of a branch 302 with which the master control unit 310 is communicatively coupled may be configured to carry out bidirectional communication with one another, in other words may be configured to communicate with one another in a bidirectional manner. The interface node 306 of each branch 302 may thus be configured to receive data from the master control unit 310 and to transmit (in other words send) data to the master control unit 310.

[0082] The master control unit 310 and the respective interface node 306 of a branch 302 may be communicatively coupled with one another via a wired connection 316. In some aspects, the wired connection 316 coupling a branch 302 with the master control unit 310 may be of different type with respect to the wired connection 312 within the branch 302. This configuration may take into account the fact that a master control unit 310 may be configured to carry out a plurality of functions within the host device (e.g., in the vehicle), and may thus be configured to communicate according to a different wired communication protocol with respect to the wired communication protocol used internally within a branch 302.

[0083] Stated in a different fashion, considering a branch 302, the network nodes 304 in the branch 302 may be configured to communicate with one another according to a first serial communication protocol for wired communication, and the interface node 306 of the branch 302 may be configured to communicate with the master control unit 310 according to a second serial communication protocol for wired communication. The first serial communication protocol may be different from the second serial communication protocol.As an example, the first serial communication protocol may be OSP. As an example, the second serial communication protocol may be one of a CAN protocol, a Local Interconnect Network (LIN) protocol, an Ethernet protocol, and the like.

[0084] In a corresponding manner, considering a branch 302, the wired connection 312 between nodes 304 within the branch 302 may be configured to support the first serial communication protocol, and the wired connection 316 between the interface node 306 of the branch 302 and the master control unit 310 may be configured to support the second serial communication protocol. The wired connection 312 within the branch 302 may thus be different compared to the wired connection 316 between the branch 302 and the master control unit 310, e.g. in terms of number of conductive lines, in terms of communication components (e.g., resistors, capacitors), etc. For example, the wired connection 316 between the branch 302 and the master control unit 310 may be a bus for the second communication protocol, e.g. a standard automotive bus, e.g. a CAN bus, a LIN bus, an Ethernet bus, and the like. For example, all the branches 302 may be coupled to the same bus that is coupled to the master control unit 310.

[0085] Considering a configuration with different communication protocols, the communication circuitry 314 of the interface node 306 of a branch 302 may include a first portion configured to communicate according to the first communication protocol (with the network node 308 coupled with the interface node 306), and a second portion configured to communicate according to the second communication protocol (with the master control unit 310). It is however understood that also a configuration in which the master control unit 310 communicates with the branches 302 using the same wired communication protocol as for the internal communication in a branch 302, and via the same type of wired connection may be provided.

[0086] It is understood that the representation in FIG.3A may be simplified for the purpose of illustration, and the network 300 may include additional components with respect to those shown. As an example, the network 300 may include a power supply or may be configured for coupling with a power supply. The power supply may be configured to deliver power (e.g., a voltage) to the network nodes 304 of the branches 302. As an example, the power supply may be configured to deliver to each node 304 a voltage in the range from 1 V (Volts) to 50 V, for example the power supply may be configured to deliver a voltage of 12 V, 24 V, or 48 V to each network node 304. In this configuration, each network node 304 may further include a supply port coupled with a supply line for receiving the power from the power supply.

[0087] As another example, the network 300 may include a clock generator or may be configured for coupling with a clock generator. The clock generator may be configured to deliver a clock signal to the network nodes 304 of the branches 302. A network node 304 (e.g., the communication circuitry 314) may use the clock signal for timing the communication with the adjacent network node(s) 304, e.g. to control the signal level (voltage level) at an electrically conductive line according to the timing defined by the clock signal.

[0088] FIG.3B shows a schematic block diagram of a master control unit 320 for use in the network 300, according to various aspects. Illustratively, the master control unit 320 may be an exemplary configuration of the master control unit 310. It is understood that the configuration in FIG.3B is exemplary, and a master control unit may include additional, less, or alternative components. In general, the master control unit 320 may include a processor 322, a memory 324, communication circuitry 326, and software 328 to carry out the functionalities described herein.

[0089] The processor 322 may be configured to generate instructions to instruct an operation of the network nodes 304 of the branches 302, and cause a transmission of the instructions via the communication circuitry 326. For example, the processor 322 may generate instructions specific for a target branch 302, or for a specific target node 304 within a branch 302. As another example, the processor 322 may generate instructions for all the branches 302 (or for a subset including multiple branches 302), e.g. to initialize an operation at startup. For example, the memory 324 may store a set of possible instructions that the processor 322 retrieves for transmission to the branches 302.

[0090] The processor 322 may be further configured to receive data from the branches 302, e.g. representative of an operation at a branch 302, of a state of a branch 302, of a state of a node 304, and the like. The processor 322 may cause a storage of the received data in the memory 324, e.g. to create a log of the network 300. The processor 322 may further process the received data to analyze the state of the network 300. For example, the processor 322 may receive data indicative of a malfunction of a branch 302 or of a node 304 of the branch 302, and may generate a corresponding instruction, e.g. to stop an operation of the branch 302 or of the node, to set different operating parameters for the branch 302 or the node 304, to send an alert signal to a user, and the like. The processor 322 may execute programming included within the software 328 to perform an analysis of the data received from the branches 302. For example, the memory 324 may be configured to store the software 328 to be executed by the processor 322.

[0091] The communication circuitry 326 may be configured to enable wired communication between the master control unit 320 and the interface nodes 306 of the branches 302. The communication circuitry 326 may thus include communication hardware to enable a wired connection with the interface nodes 306. For example, the communication hardware may include a plurality of input / output ports, resistors, capacitors, switches (e.g., transistors), and the like, to carry out a wired-based communication. In some aspects, the master control unit 320 may further include communication circuitry for wireless communication, e.g. to communicate with other types of devices (e.g., within a vehicle).

[0092] As discussed, there may be different configurations possible for the interface node 306 of a branch 302. In general, the interface node 306 may be configured as a primary node (see FIG.3C), illustratively as a local master node for the branch 302, or as a bridge node (see FIG.3D) without any leading role but simply acting as a “translator” between the master control unit 310 and the network nodes 304 of the branch 302. In this regard, the interface nodes 306 of different branches 302 may be configured in the same manner or in a different manner.

[0093] In one exemplary configuration the interface node 306 of each branch 302 may be configured as a primary node that controls the operation of the secondary nodes 308 of the branch 302. As another exemplary configuration the interface node 306 of each branch 302 may be configured as a bridge node that converts messages from the wired communication protocol used by the master control unit 310 into messages according to the wired communication protocol of the network nodes 304 of the branch 302. As a further exemplary configuration one or more branches 302 may include an interface node 306 configured as a primary node, and one or more other branches 302 may include an interface node 306 configured as a bridge node.

[0094] FIG.3C shows an interface node configured as primary node 330, and FIG.3D shows an interface node configured as bridge node 360. Illustratively, the primary node 330 and bridge node 360 may be possible configurations of the interface node 306 of a branch 302.

[0095] In general, a primary node 330 and / or bridge node 360 may include communication circuitry 332, 362 processing circuitry 334, 364 and input / output ports 340, 342, 370, 372. In some aspects, the communication circuitry 332, 362 may be configured to enable communication according to two different communication protocols, e.g. on to / from the master control unit 310 and another one to / from the secondary nodes 308 of the branch 302. The communication circuitry 332, 362 may thus be configured to enable a communicative coupling of the primary node 330 or bridge node 360 with at least one secondary network node 308 and further with the master control unit 310. Although not shown, in some aspects a primary node 330 and / or bridge node 360 may further include a memory.

[0096] The communication circuitry 332, 362 may thus be configured to enable a first communication according to the first communication protocol used in the branch 302 (e.g., OSP), and further to enable a second communication according to a second communication protocol used by the master control unit 310. The communication circuitry 332, 362 may illustratively include a first circuit portion 336, 366 configured to carry out a first communication according to the first communication protocol with the network node(s) 308 of the branch 302. The communication circuitry 332, 362 may further include a second circuit portion 338, 368 configured to carry out a second communication according to the second communication protocol with the master control unit 310.

[0097] The first circuit portion 336, 366 may thus include one or more components to control or define a voltage level at an input / output port 340, 370 (e.g., at one or more electrically conductive lines, e.g. as described in FIG.2D) at which the node 330, 360 is or will be coupled with a secondary network node 308. The second circuit portion 338, 368 may include one or more components to control or define a voltage level at an input / output port 342, 372 (e.g., at one or more electrically conductive lines) at which the node 330, 360 is or will be coupled with the master control unit 310.

[0098] The first circuit portion 336, 366 may thus be configured to carry out a first communication with first communication parameters, such as a first timing (e.g., synchronous or asynchronous), a first encoding, first voltage levels to define logic levels, a first message structure, a first data rate, etc. The second circuit portion 338, 368 may be configured to carry out a second communication with second communication parameters, such as a second timing, a second encoding, second voltage levels to define logic levels, a second message structure, a second data rate, etc. One or more of the first communication parameters may be different from the corresponding second communication parameters.

[0099] The communication circuitry 332, 362 may thus be configured to translate the physical layer of the communication protocol of the master control unit 310 into the physical layer of the communication protocol of the branch 302 and vice versa. The physical layers may differ in one or more layer parameters, such as number of electrically conductive lines, type of electrically conductive lines, the layout of input / output pins, the voltages, and the like.

[0100] The specific configuration of the first and second circuit portions 336, 338, 366, 368 and of the input / ports 340, 342, 370, 372 may be adapted depending on the communication protocols. In this regard, a number of pins, a type and / or number of resistors, a type and / or number of switch elements, etc. may be adapted depending on the first and second communication protocols. Considering OSP protocol, as discussed in relation to FIG.2C, theinput / output port 340, 370 for coupling with the secondary network node 308 may include two input / output pins for coupling with two electrically conductive lines.

[0101] In some aspects, the hardware of the circuit portions 332, 362 may be specific for the communication protocols. Illustratively, the first circuit portion 336, 366 may include hardware components that enable communication using the first communication protocol, and the second circuit portion 338, 368 may include hardware components that enable communication using the second communication protocol.

[0102] Turning to the configuration of the interface node as primary node 330, the primary node 330 may be configured to control (e.g., to instruct) the operation of the secondary network nodes 308 of the branch 302. Illustratively, the processing circuitry 334 may be configured to generate instructions for the secondary network nodes 308 and cause a transmission of the instructions to the secondary network nodes 308 via the communication circuitry 332. Illustratively, the primary node 330 may be configured to act as a branch master capable of bidirectional communication with the master control unit 310, and further capable of generating instructions to instruct the operation of the secondary nodes 308.

[0103] The processing circuitry 334 of the primary node 330 may thus be configured to control a communication within the network branch 302, e.g. configured to control a data transfer over the daisy chain of network nodes 308. Illustratively, the processing circuitry 334 may be configured to cause a transmission of messages along the chain of secondary nodes 308, and to prompt a response from one or more of the secondary nodes 308. As mentioned above, the primary node 330 may be or include a microcontroller to carry out the control of the secondary network nodes 308.

[0104] In this configuration, the primary node 330 may be configured to receive a message 350 from the master control unit 310, and to generate one or more instructions for controlling an operation of the secondary nodes 308 based on the message 350 received from the master control unit 310. The primary node 330 may further be configured to cause a propagation of the generated instructions along the daisy chain of secondary nodes 308. Illustratively, the primary node 330 may be configured to translate the message from the master control unit (e.g., including instructions with a high level of abstraction) into specific instructions for the local operation of the branch 302. As an example, the message from the master control unit may include an abstract instruction such as “initialize operation”, and the primary node 330 may be configured to generate specific instructions to implement the “initialize operation” (e.g., power up, setting voltage levels, carrying out a diagnostic process, and the like).

[0105] As shown, the primary node 330 (e.g., its communication circuitry 332) may be configured to receive a (first) message 350 from the master control unit, carry out a processing 352 of the message 350 (at the processing circuitry 334), and generate a (further) second message 354 addressed to the secondary nodes 308 based on the processing 352 of the first message 350. The processing 352 may include, for example, interpreting a (first) instruction contained in the first message 350, and generating one or more (second) instructions addressed to the secondary nodes 308 based on the processing of the first instruction. As another example, the processing 352 may include interpreting a (first) request for information contained in the first message 350, and generating one or more (second) requests for information addressed to the secondary nodes 308 based on the processing of the first request for information.

[0106] In some aspects, the processing 352 may include converting an instruction contained in the message 350 from the master control unit 310 into branch-specific instructions (low-level instructions) to control the operation of one or more of the secondary network nodes 308 to implement the instruction contained in the message 350.

[0107] As an example, the second message 354 may include the address of a target secondary node 308, e.g. to control an operation of that specific node 308, or to retrieve information from that specific node 308 (illustratively, prompting a response from a secondary node 308). For example, as shown in FIG.3C, the second message 354 may include a plurality of second messages, e.g. a message 354(1) addressed to a first secondary node 308, a message 354(2) addressed to a second secondary node 308, a message 354(N) addressed to an N-th secondary node 308. As another example, the second message 354 may be addressed to all the secondary nodes 308, e.g. to control a common operation of the secondary nodes 308 or to retrieve information from all the secondary nodes 308.

[0108] As mentioned above, the communication between the master control unit 310 and the interface node (as primary node 330) may be bidirectional. The primary node 330 may thus be configured to generate a message addressed to the master control unit 310 and transmit the message to the master control unit 310. The content of the message may include any suitable information, e.g. depending on the initial command from the master control unit 310. For example, the message may include information on the operation of the secondary nodes 308, e.g. an operating state, operating parameters, and the like. As another example, the message may include a confirmation that the command from the master control unit 310 has been successfully executed and completed.

[0109] In some aspects, the primary node 330 may be configured to control an operation of the secondary network nodes 308 independently from the master control unit 310, e.g. even inabsence of a corresponding message / command from the master control unit 310. In this scenario, in addition to receiving and processing commands from the master control unit 310, the primary node 330 may be further configured to autonomously instruct an operation of the secondary nodes 308. This configuration may enhance the efficiency of the operation of the branch, by allowing the primary node 330 to act locally without having to wait for a corresponding prompt from the master control unit 310.

[0110] The operations that the primary node 330 may instruct independently of the master control unit 310 may be of relatively low complexity, or may be preparatory operations for the functionality to be carried out by the secondary nodes 308. Illustratively, the primary node 330 may decide locally and perform some(simple) tasks autonomously without contacting the master control unit 310, e.g. run a temperature stabilization routine, instruct a calibration of the nodes 308, perform color-to-PWM calculations, and the like.

[0111] According to various aspects, the primary node 330 and the immediately adjacent secondary node 308 with which the primary node 330 is coupled may be configured to communicate with one another using Manchester encoding. Illustratively, the primary node 330 and the immediately adjacent secondary node 308 in the chain may be connected via a single- ended bus and may the primary node 330 may communicate data to the secondary node 308 using a single-wire Manchester coding signal. This configuration may facilitate the operation at the primary node 330 and simplify the configuration of the circuitry at the secondary node 308. Illustratively, the communication circuitry 332 of the primary node 330 may be configured to encode a signal to be transmitted according to Manchester coding, and the communication circuitry 314 of the secondary node 308 may be configured to decode a received signal according to Manchester coding. The details of Manchester encoding and Manchester code signals are known in the art.

[0112] Turning to the configuration of the interface node as bridge node 360, the bridge node 360 may be configured to translate a message from the master control unit 310 into a message according to the communication protocol used within the branch 302, without carrying any interpretation of the data contained in the message. Illustratively, the bridge node 360 may simply forward the message from the master control unit 310 in a format that the secondary network nodes 308 are capable of interpreting, without taking any action based on the content of the message. By way of illustration, the bridge node 360 may act as an “interpreter” between the master control unit 310 and the secondary network nodes 308 of the branch. Considering the OSP context, the bridge node 360 (e.g., its processing circuitry 364) may extract the payload portion of the message and forward the command to the secondary nodes 308. In this scenario,the actions / instructions that would be taken by the primary node of the branch 302 are taken instead by the master control unit 310. Illustratively, in case the interface node is configured as a bridge node 360, the branch 302 may be free of a primary node 330 (of a local master node).

[0113] In this scenario, the communication circuitry 362 of the bridge node 360 may be configured to provide a bridging interface between two different communication protocols, thus acting as an “interpreter” or “translator” between the branch 302 and the master control unit 310. In this regard, the communication circuitry 362 may be configured to receive a first message 380-1 from the master control unit 310 configured according to a wired communication protocol. The processing circuitry 364 may carry out a processing 382 to transform the first message 380-1 into a second message 380-2 configured according to another wired communication protocol of the branch 302. The information contained in the first message 380-1 may correspond to the information contained in the second message 380-2 (e.g., instructions), with the format of the messages being different according to the respective wired communication protocol.

[0114] Considering bidirectional communication also the opposite scenario may occur. The communication circuitry 362 may thus be configured to receive the second message 380-2 configured according to the wired communication protocol of the branch 302, and transform the second message 380-2 into a first message 380-1 configured according to the wired communication protocol of the master control unit 310, e.g. to deliver data to the master control unit 310.

[0115] The processing circuitry 364 may thus be configured to extract information from the first message 380-1 and embed the extracted information into the second message 380-2, illustratively into a structure compatible with the second communication protocol (or vice versa). Considering the OSP context, the processing circuitry 364 may extract information from the first message 380-1 and embed the extracted information into the payload portion of an OSP telegram for transmission to the network nodes 308.

[0116] As discussed in relation to the primary node 330, the message 380-2 to the secondary network nodes 308 may include a plurality of messages, e.g. each addressed to a respective secondary network node 308. For example, as shown in FIG.3D, the second message 380-2 may include a plurality of second messages, e.g. a message 380-2(1) addressed to a first secondary node 308, a message 380-2(2) addressed to a second secondary node 308, a message 380-2(N) addressed to an N-th secondary node 308, etc. As another example, the second message 380-2 may be addressed to all the secondary nodes 308, e.g. to control a commonoperation of the secondary nodes 308 or to retrieve information from all the secondary nodes 308.

[0117] As a possible configuration for the scenario in which the interface node 306 is a primary node 330 and / or the scenario in which the interface node 306 is a bridge node 360, the network nodes 304 of a branch 302 may be configured to support a plurality of physical modes. For example, the network nodes 304 of at least one branch 302, or more than one branch 302, or each branch 302 may be configured to support a plurality of physical modes. Illustratively, the network nodes 304 of a branch (e.g., the respective communication circuitry 414) may be configured to support a plurality of different physical modes for the propagation of information along the chain. Illustratively, a network node 304 may be configured to communicate with the adjacent network node(s) 304 using one physical mode among a plurality of possible physical modes for the communication. For example, the selection of which physical mode to use may be based on an instruction received at the network node 304 (e.g., from the master control unit of the network 310, or from the local master node 330 of the branch). The availability of multiple physical modes enhances the flexibility of the arrangement, by tailoring the type of communication according to system requirements.

[0118] Illustratively, a network node 304 may be configured to communicate via the wired connection according to any suitable combination of signal levels at the electrically conductive lines to implement the selected physical mode. For example, considering the configuration in FIG.2D, a network node 304 may be configured to control the pull-up and pull-down resistor(s) according to the selected physical mode. The selection of the physical mode may be done using a certain combination of pull-up and pull-down resistors on each of the two communication lines. Each port of a network node 304 may support a different physical mode.

[0119] The specific physical modes may be defined according to desired configuration of the branch 302, e.g. according to the desired communication protocol to be used in the branch 302. In the following some examples are provided that have been designed for use in particular with the OSP protocol, but it is understood that the physical modes described herein may also be for use with other communication protocols, and also that the network nodes 304 may be configured to support additional, less, or alternative physical modes.

[0120] According to various aspects, a network node 304 (e.g., a secondary node 308) may be configured to receive an instruction (from the master control unit 310, or from a local primary node 330) indicative of a physical mode to be selected for communication. The network node 304 may be configured to select the indicated physical mode and carry out a communication(with other network nodes 304) according to the selected physical mode. The selected physical mode may define the physical way in which data are transmitted from the network node 304. According to various aspects, one or more network nodes 304 (e.g., in one branch 302, or a plurality of branches 302, or each branch 302) may have a hardcoded physical mode. Illustratively, the hardcoding defines a single physical mode available for that network node(s) 304, e.g. to impose a preferred way to communicate data taking into account system considerations. The hardcoding may be provided, for example, for specialized secondary nodes 308 for use in one specific location where the physical mode selection is hardcoded by design (for instance, MCU-to-OSP nodes and OSP-to-OSP nodes, etc.). In some aspects, there may be a standard physical mode supported by all network nodes 304 in a branch 302 and switching to the preferred mode may be done by command.

[0121] As an example, the plurality of physical modes supported / selectable by a network node 304 may include a single-ended bidirectional mode, a differential mode, an end-of-line (EOL) mode, and a single-wire unidirectional mode.

[0122] The single-ended bidirectional mode (also referred to as MCU mode) may be provided only for the connection between a primary node 330 of a branch 302 and the adjacent secondary node 308. Illustratively, such mode may be restricted to the connection between the local master node and the first slave node. According to the single-ended bidirectional mode, data may be transmitted to the secondary node 308 (from the primary node 330) using a single wire and Manchester encoding (to simplify the integrated circuit of the secondary node 308). In the reverse direction (from secondary node 308 to primary node 330), data is transmitted using clock and data (to enable efficient use of standard controllers). As an alternative type of connection between the primary node 330 and the adjacent secondary node 308 a standard SPI or universal asynchronous receiver / transmitter (UART) bus may be used.

[0123] The differential mode may be the preferred mode for communication between two secondary nodes 308 in a branch 302. The communication between two secondary nodes 308 may utilize a differential signaling scheme where data is encoded using voltage differences between two wires. For clock and data recovery, the information is further coded, for example, using Manchester coding. This is the preferred mode for communication between two secondary nodes 308 to minimize electromagnetic interferences.

[0124] The single-wire unidirectional mode may allow to use additional transceiver units to translate from a single-ended signal to some other signaling technique (see FIG.5C and FIG.5D). For instance, it can be used to bridge larger distances between two secondary nodes 308 using a pair of CAN-FD transceivers and a CAN physical connection.

[0125] The EOL mode may signal to secondary node 308 that the node is the last node in the daisy chain. This information enables the propagation of information along the chain, allowing the last node to send information back (in case of a linear chain) or to forward information to the primary node (in case of a loopback configuration).

[0126] FIG.4A shows a message flow diagram 400 to illustrate an exemplary message flow in a branch 302 including a primary node 330 as interface node with the master control unit 310. As mentioned, the master control unit 310 may send a first message 350 to the primary node 330. For example, the master control unit 310 (e.g., master BCU) may send a command to the local branch master 330, e.g. a command at a higher level of abstraction (e.g., “initiate system”, “play animation #1”, “set color pattern #5”, etc.), which may be adapted depending on the functionality implemented via the secondary nodes 308 (e.g., light emission, sensing, etc.). For example, considering the automotive context, the master control unit 310 may send the command via an automotive standard bus.

[0127] The primary node 330 may carry out a processing 352 of the first message 350, e.g. of the command, to generate a second message 354 based on the content of the first message 352. For example, the primary node 330 may translate the command from the master control unit 310 into individual commands for the secondary nodes 308 in the branch 302. In an exemplary configuration, the primary node 330 may generate a plurality of second messages 354, e.g. one for each secondary node 308, including specific instructions for the target node 308 and further including the address of the target node 308. The type of instructions may depend on the type of nodes 308 and on the type of communication protocol used. As an example, considering “initiate system” as command from the master control unit 310, the second message(s) 354 may include instructions such as “send init - wait for response - check number of nodes - load calibration - set default values”, e.g. considering the OSP context.

[0128] The secondary nodes 308 may receive the instructions from the primary node 330, and perform a corresponding function based on the instructions. For example, if the message 354 is not addressed to that node 308, the secondary node 308 may simply forward the message further along the chain (until it reaches the target node 308), without carrying out any further action. Illustratively, a node 308 may forward the telegram not intended for a specific node from one port to the other port (so the message may propagate along the chain). If a node 308 receives a message intended for that node 308, the circuitry of the node 308 may analyze the message and execute any instruction contained in the message. If the instructions prompt a response, the node 308 may generate a response message for the primary node 330 and cause a propagation of the response message to the primary node 330 along the chain.

[0129] In the exemplary flow diagram 400, the primary node 330 may generate a first message 354(1) addressed to the first secondary node 308-1 (illustratively, the adjacent node 308 in the chain). Upon receiving the first message 354(1) the first secondary node 308-1 may carry out the instructions in the message and, if prompted, generate a first response message 356(1) and cause a delivery of the first response message 356(1) to the primary node 330. The primary node 330 may further generate an N-th message 354(N) addressed to the N-th secondary node 308-N. In this scenario, the first node 308-1 (and the other nodes) simply forwards the N-th message 354(N) refraining from analyzing its content (other than the address portion) and refraining from carrying out the instructions contained in the message 354(N). The N-th node 308-N may receive the N-th message 354(N), carry out the instructions and, if prompted, generate an N-th response message 356(N) for the interface node 506.

[0130] The communication circuitry 314 of a secondary node 308 may thus cause a transmission of the response message 356(1), 356(N) to the primary node 330. Illustratively, after having generated the response message 356(1), 356(N), the communication circuitry 314 of the active secondary node 308 may initiate the transmission of the response message 356(1), 356(N) along the daisy chain until the response message 356(1), 356(N) reaches the primary node 330. Considering the linear daisy chain the response message 356(1), 356(N) may propagate back along the chain, whereas in the ring daisy chain the response 356(1), 356(N) may propagate forward and then loop-back from the last node to the primary node 330.

[0131] The secondary node 308 that generated the response message 356(1), 356(N) may thus transmit the response message 356(1), 356(N) to a neighboring node 308 (via the wired connection 312, according to the wired communication protocol, e.g. OSP). The neighboring node 308 may receive the response message 356(1), 356(N), determine that the response message 356(1), 356(N) is addressed to the primary node 330, and forward the response message 356(1), 356(N) along the chain in direction of the primary node 330. The forwarding of the response message 356(1), 356(N) may be repeated until the response message 356(1), 356(N) reaches the primary node 330.

[0132] The type of instructions addressed to a secondary node 308 may be adapted in any suitable manner, e.g. depending on the desired operation to be implemented at the secondary node 308. For example, an instruction may cause the secondary node 308 to start its functionality, e.g. light emission, a sensing process, and the like. For example, an instruction may cause the secondary node 308 to operate using certain parameters, e.g. a certain voltage, a certain light intensity, a certain duration of a sensing process, and the like. As a further example,an instruction may cause the secondary node 308 to stop its operation, or to report a diagnostics indicative of possible malfunctions at the node 308.

[0133] The content of the response message 356(1), 356(N) from a secondary node 308 to the primary node 330 may vary depending on the prompt from the primary node 330 and from the instructions from the master control circuit 310. For example, a response message 356(1), 356(N) may include the value of an operating parameter of the node 308, e.g. an operating temperature, an operating voltage, an intensity of emitted light, and the like. As another example, a response message 356(1), 356(N) may include the result of a sensing process carried out by the node, e.g. an instant value of a sensed quantity, an average value over time, and the like. As a further example, a response message 356(1), 356(N) may include an operating state of the node 308, e.g. sleep, idle, active, measuring, emitting light, etc. As a further example, a response message 356(1), 356(N) may include a condition of the node 308, e.g. to indicate the presence of a malfunction or possible malfunction at the node 308.

[0134] The primary node 330 may prompt an individual response from a single target secondary node 308, or may prompt a collective response from all the secondary nodes 308, depending on the desired operation and / or on the initial command from the master control unit. As mentioned, the primary node 330 may further transmit data (a message 358) to the master control unit 310.

[0135] FIG.4B shows a message flow diagram 450 to illustrate an exemplary message flow in a branch 302 including a bridge node 360 as interface node with the master control unit 310. As mentioned, the master control unit 310 may send a first message 380-1 configured according to the wired communication protocol of the master control unit to the bridge node 360. For example, the master control unit 310 (e.g., master BCU) may send a telegram / command to the branch bridge 360 using an automotive standard bus with a command sequence as payload (for instance: “send init - wait for response - check number of nodes - load calibration - set default values”). For example, the automotive standard bus may be an Ethernet bus.

[0136] The bridge node 360 may extract the command from the first message 380-1 and insert it into a second message 380-2 according to the wired communication protocol of the branch 302 (e.g., OSP). Illustratively, the bridge node 360 extracts the payload and sends the individual commands as individual messages for the nodes in the attached branch 302, e.g. using the OSP. For example, the bridge node 360 may send a message 380-2(1) to the first secondary node 308-1,. . ., and an N-th message 380-2(N) to the N-th secondary node 308(N).

[0137] The secondary nodes 308 may generate, if prompted, a response message for the master control unit 310, e.g. a first response message 384-2(1) from the first secondary node308-1, an N-th response message 384-2(N) from the N-th secondary node 308-N, etc. The response message(s) from the secondary node(s) 308 may be configured according to the wired communication protocol of the branch 302, and the bridge node 360 may convert the response message(s) into a response message 384-1(1), 384-l(N) according to the wired communication protocol of the master control unit 310. Illustratively, the bridge node 360 may pack incoming messages from the secondary nodes 308 (e.g., OSP messages) into a response frame towards the master control unit 310.

[0138] Each secondary network node 308 may receive and send messages from / to the bridge node 360 according to the communication protocol of the branch 302 (e.g., OSP). As discussed in relation to FIG.4A, the receiving / sending may include forwarding of messages not intended / addressed for a specific node from one port to the other port (so the messages may propagate along the chain). If a node 308 receives a message intended for the node 308, the node 308 analyzes the message and executes the commands included therein. If a response is required, the node 308 prepares and sends this response back to the bridge node 360. In contrast to the case with the primary node 330, the bridge node 360 does not interpret the data or decide locally (for example, autonomously run a temperature stabilization sequence). Instead, all decisions lie at the master control unit 310.

[0139] FIG.5A to FIG.5D show exemplary configurations 500a-500d of a branch 500 (illustratively, of a sub-network 500) for use in the proposed architecture. Illustratively, the configurations 500a-500d of the branch 500 may be exemplary realizations of a branch 302 of the network 300. In general, a branch 500 may be configured according to a linear daisy chain topology in which the network nodes are configured for bidirectional communication, as shown for the configuration 500a, 500c in FIG.5A and FIG.5C. Alternatively, a branch 500 may be configured according to a loopback daisy chain topology in which the network nodes are configured for unidirectional communication, as shown for the configuration 500b, 500d in FIG.5B and FIG.5D.

[0140] In the linear daisy chain topology each network node may be configured to transmit and receive data to / from the adjacent network nodes 308, so that information may propagate from the interface node 306 (a primary node 330 or bridge node 360) to the end of the chain and then propagate back through the chain to reach the interface node 306 (for further forwarding to the master control unit 310). In the loopback daisy chain topology each network node 308 may be configured to receive data only from the preceding node 308 in the chain and to transmit data only to the following node 308 in the chain. Considering the interface node 306 (a primary node 330 or bridge node 360) as initial node of the chain, the final node 308 maythen be coupled back to the interface node 306, so that information may propagate from the interface node 306 to the end of the chain and then propagate back via the loopback connection to the interface node 306 (for further forwarding to the master control unit 310).

[0141] In a simple configuration, as shown in FIG.5 A and FIG.5B, the network nodes 306, 308 of a branch 500 may be integrated on one substrate 502. Illustratively, the network nodes 306, 308 may be disposed (e.g., formed) on the same substrate 502. The substrate 502 may be for example a rigid substrate. As another example, the substrate 502 may be a flexible substrate, e.g. to facilitate disposing the branch 500 in more complex geometries in the host device. As an example, the substrate 502 may be a printed circuit board (PCB).

[0142] In other aspects, as shown in FIG.5C and FIG.5D, the network nodes 306, 308 of a branch 500 may be integrated on a plurality of separate substrates 502-1, 502-2. Considering the exemplary configuration in FIG.5C and FIG.5D, a first subset of network nodes 306, 308 may be disposed on a first substrate 502-1 (e.g., a first PCB) and a second subset of network nodes 308 may be disposed on a second substrate 502-2 (e.g., a second PCB). This configuration may facilitate the scaling of the number of nodes in the branch, by providing a “modular” arrangement in which additional nodes (e.g., additional secondary nodes 308) may be provided in a simple manner by coupling additional substrates to the existing chain.

[0143] As shown in FIG.5C and FIG.5D, the interface node 306 and one or more secondary nodes 308 (e.g., a first plurality of secondary nodes 308) may be integrated on the first substrate 502-1. One or more further secondary nodes 308 (e.g., a second plurality of secondary nodes 308) may be integrated on the second substrate 502-2. Optionally, further secondary nodes 308 may be integrated on a third substrate, etc.

[0144] Considering the multi-branch architecture (e.g., of the network 300), the branches may be configured in the same manner in terms of integration on a substrate, or in a different manner. For example, all the branches 302 in the network 300 may include network nodes 304 integrated in a same (respective) substrate 502. As another example, all the branches 302 in the network 300 may include network nodes 304 integrated in a plurality of (respective) substrates 502-1, 502-2. As a further example, at least one branch 302 may include network nodes 304 integrated in a same (single) substrate 502, and at least one other branch 302 may include network nodes 304 integrated in a plurality of substrates 502-1, 502-2.

[0145] In the configuration 500c, 500d with a plurality of substrates 502-1, 502-2, the branch 500 may further include a transceiver element on each substrate 502-1, 502-2 to enable a communicative coupling between the branch portions in the different substrates 502-1, 502-2. Illustratively, the branch 500 may include a first transceiver element 504-1 on the first substrate502-1 and a second transceiver element 504-2 on the second substrate 502-2 (and a third transceiver element on a third substrate, etc.). The first transceiver element 504-1 and the second transceiver element 504-2 may be coupled with one another over a wired connection 506 to enable a transfer of data between the network nodes 306, 308 on the first substrate 502-1 and the network nodes 308 on the second substrate 502-2. A transceiver element 504-1, 504-2 may illustratively be a transceiver node including transceiver circuitry to transmit / receive data to / from the network nodes 308.

[0146] Illustratively, the first transceiver element 504-1 may be coupled with the last network node 308 in the chain in the first substrate 502-1. The first transceiver element 504-1 may be further coupled with the second transceiver element 504-2, and the second transceiver element 504-2 may be further coupled with the first node in the chain in the second substrate 502-2. The first transceiver element 504-1 may thus propagate the information to the second transceiver element 504-2 for further propagation along the chain.

[0147] Depending on the topology of the branch 500, the wired connection 506 between the transceiver elements 504-1, 504-2 may support bidirectional communication (in FIG.5C) or unidirectional communication (in FIG.5D). The transceiver elements 504-1, 504-2 may communicate with one another using the same protocol as the network nodes 306, 308, or may communicate with one another using a different wired communication protocol. In case of different protocol, the wired connection 506 between the transceiver elements 504-1, 504-2 may have a different configuration compared to the wired connection 312 between nodes 306, 38 in the branch (or between a node and the transceiver element 504-1, 504-2). The use of a different protocol for the transceiver elements 504-1, 504-2 may provide a simpler, yet efficient configuration, considering that the transceiver elements 504-1, 504-2 do not need to carry out an interpretation of the data, or addition of information to the data, etc.

[0148] A transceiver element 504-1, 504-2 (and the wired connection 506) may thus be configured according to the communication protocol used for inter-substrate communication. In a preferred configuration, a transceiver element 504-1, 504-2 may be configured as a CAN transceiver, e.g. as a CAN-FD transceiver. In this scenario the transceiver elements 504-1, 504-2 may be configured to communicate with one another using a CAN protocol (e.g., CAN-FD protocol) over a CAN bus.

[0149] FIG.6A to FIG.6C show exemplary configurations of a serial communication network 600a, 600b, 600c. Illustratively, FIG.6A to FIG.6C show exemplary realizations of the network 300. It is understood that the aspects discussed in relation to the network 300 may apply in a corresponding manner to the network 600a, 600b, 600c, and vice versa.

[0150] FIG.6 A illustrates a network 600a including a plurality of branches (a first branch 602a- 1 and a second branch 602a-2) in which the interface node coupled with the master control unit 310 is a primary node 330 that controls the operation of the secondary nodes of the branch 308. For example, the primary node(s) 330 may be coupled with the master control unit 310 via a standard automotive bus, e.g. CAN, LIN, Ethernet and the like.

[0151] As an example, the primary node 330 may be coupled with the adjacent network node 308 (the first secondary network node 308 of the chain) via a single ended bus to simplify operation by the primary node 330. Bidirectional differential signaling may be provided between secondary network nodes 308 to minimize electromagnetic interference. As shown, a branch 602a-2 may include transceiver elements 504-1, 504-2 (e.g., CAN-FD) to couple portions of the branch disposed on different substrate. For example, a single-wire unidirectional mode may be implemented to integrate the transceiver nodes in the chain. As an exemplary configuration, the transceiver elements 504-1, 504-2 may communicate with one another via a CAN bus.

[0152] By way of illustration, the configuration 600a may thus include a master control unit 310 (BCU) connected via some standard bus to one or more branch control units 330 (acting as branch master) connected (e.g., via the OSP) to many slave nodes arranged in a serial chain (daisy chain) having a bidirectional communication line between each two participating nodes. The nodes 308 may support different physical modes and a message / telegram-based communication protocol with low overhead and diagnostic capabilities (e.g., OSP).

[0153] FIG.6B illustrates a network 600b including a plurality of branches (a first branch 602b- 1 and a second branch 602b-2) in which the interface node coupled with the master control unit 310 is a bridge node 360 that acts as a translator from the bus connecting the master control unit 310 to the bridge node 360 and the bus connecting the nodes in the branch 602b-l, 602b-2. The aspects discussed in relation to the network 600a may apply in a corresponding manner to the configuration of FIG.6B.

[0154] By way of illustration, the configuration 600b may thus include a master control unit 310 (BCU) connected via some standard bus to one or more branch control units 360 (acting as bridges) connected (e.g., via the OSP) to many slave nodes arranged in a serial chain (daisy chain) having a bidirectional communication line between each two participating nodes. The nodes 308 may support different physical modes and a message / telegram-based communication protocol with low overhead and diagnostic capabilities (e.g., OSP).

[0155] FIG.6C illustrates a network 600c corresponding to the configuration of FIG.6A in which the branches 602c- 1, 602c-2 have a loopback topology. As discussed, the loopback mode allows faster communication within the chain as the primary node 330 does not have to wait with the next command until the response from the previous command has been received.

[0156] By way of illustration, the configuration 600c may thus include a master control unit 310 (BCU) connected via some standard bus to one or more branch control units 360 (acting as primary node 330, or as bridge node 360 not shown) connected (e.g., via the OSP) to many slave nodes arranged in a serial chain (daisy chain) having a unidirectional communication line between each two participating nodes. The network 600c further includes a loopback communication line connecting the last node in the chain directly to the branch control unit. The nodes 308 may support different physical modes and a message / telegram-based communication protocol with low overhead and diagnostic capabilities (e g., OSP).

[0157] The terms “processor”, “processing “circuitry”, or “control circuitry” as used herein may be understood as any kind of technological entity that allows handling of data. The data may be handled according to one or more specific functions that the processor / control circuitry may execute. Further, a processor / processing circuitry / control circuitry as used herein may be understood as any kind of circuit, e.g., any kind of analog or digital circuit. A processor / processing circuitry / control circuitry may thus be or include an analog circuit, digital circuit, mixed-signal circuit, logic circuit (e.g., a hard-wired logic circuit or a programmable logic circuit), microprocessor, Central Processing Unit (CPU), Graphics Processing Unit (GPU), Digital Signal Processor (DSP), Field Programmable Gate Array (FPGA), integrated circuit, Application Specific Integrated Circuit (ASIC), etc., or any combination thereof. It is understood that any two (or more) of the processor / processing circuitry / control circuitry detailed herein may be realized as a single entity with equivalent functionality or the like, and conversely that any single processor / processing circuitry / control circuitry detailed herein may be realized as two (or more) separate entities with equivalent functionality or the like.

[0158] The term “connected” may be used herein with respect to terminals, integrated circuit elements, devices, and the like, to mean electrically connected, which may include a direct connection or an indirect connection, wherein an indirect connection may only include additional structures in the current path that do not influence the substantial functioning of the described circuit or device. The term “electrically conductively connected” that is used herein to describe an electrical connection between one or more terminals, devices, regions, contacts, etc., may be understood as an electrically conductive connection with, for example, ohmicbehavior, e.g. provided by a metal or degenerate semiconductor in absence of p-n junctions in the current path. The term “coupled” may be used herein in the same manner as the term “connected”.

[0159] The term “terminal” may be used herein to describe a location (e.g., a point) or structure of a device or of an element of the device at which a signal (e.g., an analog signal, for example a current or a voltage) may be provided and / or to which another device or element may be connected. Illustratively, a terminal may be a location or a structure that is electrically conductively connected with the device or the element. A terminal may also be referred to herein as port, pin, contact, or contact point.

[0160] The terms “path”, “electrical path”, or “electrically conductive path” may be used herein to describe an electrically conductive connection between two or more elements. A path may be understood, in some aspects, as an electrically conductive line (or trace) along which a signal (in some aspects, a current or a voltage) may travel, e.g. from a first element connected to the path to a second element connected to the path or vice versa. The term path may describe a direct path or an indirect path, wherein an indirect path may only include additional structures in the path that do not influence the substantial functioning of the described circuit or device (illustratively, that do not influence the signal traveling along the path).

[0161] As used herein, a signal that is "indicative of', “representative of’ or “representing” a value or other information (e.g., an instruction) may be a digital or analog signal that encodes or otherwise communicates the value or other information in a manner that can be decoded by and / or cause a responsive action in a component receiving the signal (e.g., in a secondary device receiving instructions from a primary device, or in a primary device receiving data from a secondary device).

[0162] As used herein, “memory” is understood as a computer-readable medium (e.g., a non transitory computer readable medium) in which data or information can be stored for retrieval. References to “memory” included herein may thus be understood as referring to volatile or non volatile memory, including random access memory (RAM), read only memory (ROM), flash memory, solid state storage, magnetic tape, hard disk drive, optical drive, among others, or any combination thereof. Registers, shift registers, processor registers, data buffers, among others, are also embraced herein by the term memory.

[0163] The word “exemplary” is used herein to mean “serving as an example, instance, or illustration”. Any embodiment or design described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments or designs.

[0164] The phrase “at least one” and “one or more” may be understood to include a numerical quantity greater than or equal to one (e.g., one, two, three, four, [...], etc.). The phrase “at least one of’ with regard to a group of elements may be used herein to mean at least one element from the group consisting of the elements. For example, the phrase “at least one of’ with regard to a group of elements may be used herein to mean a selection of: one of the listed elements, a plurality of one of the listed elements, a plurality of individual listed elements, or a plurality of a multiple of individual listed elements.

[0165] Unless specified otherwise, the term “subset” in relation to a group of elements may be understood to include a numerical quantity equal to or greater than one and less than a total number of the implied elements. Considering for example a group of ten elements, a “subset” of the group may include one, two, three, four, five, six, seven, eight, or nine elements. The term “subset” in relation to a group may thus describe a “proper subset” of the group, so that all the elements of the subset belong to the group, but at least one element of the group does not belong to the subset.

[0166] All acronyms defined in the above description additionally hold in all claims included herein.

[0167] While the invention has been particularly shown and described with reference to specific aspects, it should be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. The scope of the invention is thus indicated by the appended claims and all changes, which come within the meaning and range of equivalency of the claims, are therefore intended to be embraced.List of reference signs 308-N N-th secondary node310 Master control unit100 Network 312 Wired connection100a Network topology 314 Communication circuitry100b Network topology 316 Wired connection102 Network node 320 Master control unit104 Primary node 322 Processor106a Secondary node 324 Memory106b Secondary node 326 Communication circuitry106c Secondary node 328 Software106d Secondary node 330 Primary node108 Control circuitry 332 Communication circuitry 110 Wired connection 334 Processing circuitry 112 Communication circuitry 336 First communication portion200 Network node 338 First communication portion 200b Network node 340 Input / output port 200c- 1 Network node 342 Input / output port 200c-2 Network node 350 First message 200d Network node 352 Processing202 Communication circuitry 354 Second message204 Functional circuitry 354(1) Message for the first node204b Functional circuitry 354(2) Message for the second node206 Input / output port 354(N) Message for the N-th node206c Input / output port 356(1) First response message208 Input / output port 356(N) N-th response message208c Input / output port 358 Response message210 Driver circuit 360 Primary node212 Light emitting elements 362 Communication circuitry214 Input / output pin 364 Processing circuitry216 Input / output pin 366 First communication portion218 Input / output pin 368 First communication portion220 Input / output pin 370 Input / output port222 Electrically conductive line 372 Input / output port224 Electrically conductive line 380-1 First message226 Electrically conductive line 380-2 Second message228 Electrically conductive line 380-2(1) Message for the first node230 Resistor arrangement 380-2(2) Message for the second node232 Resistor arrangement 380-2(N) Message for the N-th node234 Supply terminal 382 Processing236 Ground terminal 384-1(1) First response message238 Communication hardware 384-2(1) First response message240 Processor 384-l(N) N-th response message300 Serial communication network 384-2(N) N-th response message302 Branches 400 Message flow diagram302-1 First branch 450 Message flow diagram302-2 Second branch 500 Branch302-N N-th branch 500a First configuration304 Network nodes 500b Second configuration306 Interface node 500c Third configuration308 Secondary nodes 500d Fourth configuration308-1 First secondary node 502 Substrate-1 First transceiver -2 Second transceiver Wired connection a Serial communication networkb Serial communication networkc Serial communication networka-l First branch b-l First branch c- 1 First branch a-2 Second branch b-2 Second branch c-2 Second branch

Claims

Claims1. A serial communication network (300) comprising: a plurality of branches (302), wherein each branch (302) comprises: a plurality of network nodes (304) connected to one another in a daisy chain configuration and configured to communicate with one another according to a wired communication protocol for serial communication, wherein the plurality of network nodes (304) in the branch (302) are connected according to a linear daisy chain topology and are configured for bidirectional communication, or wherein the plurality of network nodes (304) in the branch (302) are connected according to a loopback daisy chain topology and are configured for unidirectional communication; and a master control unit (310) common to the plurality of branches (302) and communicatively coupled with at least one network node (304, 306) of each branch (302) of the plurality of branches (302), wherein the network nodes (304) of at least one branch (302) are configured to support a plurality of physical modes for communication according to the wired communication protocol for serial communication.

2. The serial communication network (300) according to claim 1, wherein the master control unit (310) and the respective network node (304, 306) of each branch (302) with which the master control unit (310) is communicatively coupled are configured to communicate with one another in a bidirectional manner.

3. The serial communication network (300) according to claim 1 or 2, wherein, for at least one branch (302), the network nodes (304) in the at least one branch (302) are configured to communicate with one another according to a first serial communication protocol for wired communication, andwherein the network node (304, 306) of the at least one branch (302) communicatively coupled with the master control unit (310) is configured to communicate with the master control unit (310) according to a second serial communication protocol for wired communication, different from the first serial communication protocol for wired communication.

4. The serial communication network (300) according to any one of claims 1 to 3, wherein for at least one branch (302) the network nodes (304) in the at least one branch (302) are disposed on a plurality of substrates (502-1, 502-2) that are separated from one another.

5. The serial communication network (300) according to claim 4, wherein the at least one branch (302) further comprises a first transceiver element (504-1) disposed on a first substrate (502-1) of the plurality of substrates (502-1, 502-2), and a second transceiver element (504-2) disposed on a second substrate (502-2) of the plurality of substrates (502-1, 502-2), wherein the first transceiver element (504-1) and the second transceiver element (504-2) are communicatively coupled with one another, and wherein the at least one branch (302) comprises a first plurality of network nodes (304) disposed on the first substrate (502-1) and a second plurality of network nodes (304) disposed on the second substrate (502-2).

6. The serial communication network (300) according to any one of claim 1 to 5, wherein at least one network node (304) of at least one branch (302) has a hardcoded physical mode for communication according to the wired communication protocol for serial communication.

7. The serial communication network (300) according to any one of claims 1 to 6, wherein, for at least one branch (302), the network node (306) of the at least one branch (302) communicatively coupled with the master control unit (310) isconfigured as a primary node (330), the other network nodes (304) of the branch(302) are configured as secondary nodes (308), and wherein the primary node (330) is configured to instruct an operation of the secondary nodes (308). The serial communication network (300) according to claim 7, wherein the primary node (330) is configured to: receive a message (350) from the master control unit (310), and generate one or more instructions for controlling an operation of the secondary nodes (308) based on the message (350) received from the master control unit (310). The serial communication network (300) according to claim 8, wherein the message (350) comprises one or more first instructions, and wherein the primary node (330) is configured to generate one or more second instructions for the for controlling an operation of the secondary nodes (308) based on the one or more first instructions, wherein the one or more second instructions are lower level instructions compared to the one or more first instructions. The serial communication network (300) according to any one of claims 7 to 9, wherein the primary node (330) is further configured to instruct an operation of one or more of the secondary nodes (308) independently from the reception of a message (350) from the master control unit (310). The serial communication network (300) according to any one of claims 7 to 10, wherein the primary node (330) is or comprises a microcontroller.

12. The serial communication network (300) according to any one of claims 1 to 11, wherein, for at least one branch (302), the network node (306) of the at least one branch (302) communicatively coupled with the master control unit (310) is configured as a bridge node (360), the other network nodes (304) of the branch (302) are configured as secondary nodes (308), wherein the bridge node (360) is configured to: receive from the master control unit (310) a first message (380-1) according to the second serial communication protocol for wired communication; transform, without interpreting a content of the first message (380-1), the first message (380-1) into a second message (380-2) according to the first serial communication protocol for wired communication; and cause a propagation of the second message (380-2) to the secondary network nodes (308).

13. The serial communication network (300) according to any one of claims 1 to 12, wherein, for at least one branch (302), the network nodes (304) are configured to communicate with one another according to the Open System Protocol. wherein preferably in each branch (302) the network nodes (304) are configured to communicate with one another according to the Open System Protocol.

14. The serial communication network (300) according to any one of claims 1 to 13, wherein, for at least one branch (302), at least one network node (304) includes one or more light emitting elements (212) and a driver circuit (210) configured to control a light emission by the one or more light emitting elements (212), wherein preferably the one or more light emitting elements (212) comprise one or more light emitting diodes.

15. A vehicle including one or more serial communication networks (300) according to any one of claims 1 to 14.

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