A high-speed differential synchronous bus communication circuit

Abstract

The utility model discloses a high -speed difference synchronous bus communication circuit utilizes difference converter and ethernet module, realized high -speed difference synchronous communication between main communication equipment and slave communication equipment. Compared with prior art, first, adopt difference signal transmission to improve the anti -interference ability greatly, can be in the more complex electromagnetic environment stable transmission signal, second, use ethernet physical layer to transmit, make the system support higher transmission bandwidth, use CAT5 or above specification transmission network line simultaneously, reduced the wiring difficulty and cost of system, and have good expansibility. Through the introduction SPI interface, host end can with a plurality of slave communication equipment one -to -one correspondence, and through difference converter will single -end signal convert into difference signal, and this design not only improves data transmission rate, also effectively made up the deficiency of existing scheme on bandwidth and communication distance.

Description

Technical Field

[0001] This utility model relates to the field of master-slave communication technology, specifically to a high-speed differential synchronous bus communication circuit. Background Technology

[0002] With the continuous development of modern communication technology, high-speed differential synchronous communication technology has been widely used in various communication systems, especially in applications requiring long data transmission distances and high anti-interference capabilities. Compared to traditional single-ended signal transmission, differential signal transmission offers significantly improved anti-interference capabilities, effectively enhancing communication stability and data transmission rates. Furthermore, synchronous communication protocols, due to their simple structure, low cost, and high data transmission efficiency, are widely used in board-level short-distance communication. The combination of these two technologies provides technical support for various application scenarios in modern communication systems.

[0003] However, existing differential synchronous communication technologies still face some challenges in application. Traditional differential communication methods, such as RS485, CAN bus, and Ethernet, while possessing strong anti-interference capabilities and long communication distances, have limitations in bandwidth and transmission speed. For example, RS485 bus has a low communication speed and only supports half-duplex communication, making it difficult to meet the needs of applications requiring high bandwidth. While Ethernet can provide higher bandwidth, its higher cost and the need for complex link layer devices (such as switches and PHY chips) make it less advantageous in some low-cost and low-power applications.

[0004] In synchronous communication, protocols like SPI and IIC are widely used due to their simplicity and low cost. However, their shortcomings in communication distance and interference immunity pose challenges for long-distance, high-speed communication. Furthermore, existing synchronous communication protocols typically use single-ended level signals, making it difficult to guarantee signal quality over long distances or in complex environments, and resulting in transmission rates and stability that cannot meet the requirements of high-performance applications.

[0005] Therefore, based on existing technologies, how to combine synchronous communication and differential communication technologies, make full use of their advantages, and improve the bandwidth, distance, and anti-interference capability of communication systems has become an urgent problem to be solved. Utility Model Content

[0006] Therefore, this utility model provides a high-speed differential synchronous bus communication circuit to solve the problems of limited transmission distance and high cost of existing synchronous communication circuits.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A high-speed differential synchronous bus communication circuit, the circuit including a master communication device and at least one slave communication device, and a transmission cable;

[0009] The main communication device includes a host, a first differential converter, and a first Ethernet module; the SPI interface of the host is electrically connected to a first terminal of the first differential converter, the second terminal of the first differential converter is electrically connected to a first terminal of the first Ethernet module, the second terminal of the first Ethernet module is electrically connected to the slave communication device, and the third terminal of the Ethernet module is either left floating or electrically connected to the last slave communication device among the at least one slave communication device.

[0010] For each of the slave communication devices, the slave communication device includes a slave unit, a second differential converter, and a second Ethernet module; the SPI interface of the slave unit is electrically connected to a first terminal of the second differential converter, the second terminal of the second differential converter is electrically connected to a first terminal of the second Ethernet module, and the second terminal of the second Ethernet module is electrically connected via the transmission cable to a second terminal of the first Ethernet module or a third terminal of the second Ethernet module of the first target slave communication device; the third terminal of the second Ethernet module is either left floating or electrically connected to a second terminal of the second Ethernet module of the second target slave communication device.

[0011] Wherein, the first target slave communication device is the preceding slave communication device among the at least one slave communication devices that is adjacent to the slave communication device; the second target slave communication device is the following slave communication device among the at least one slave communication devices that is adjacent to the slave communication device.

[0012] Preferably, the connection between the master communication device and the at least one slave communication device is a daisy-chain connection.

[0013] Preferably, the number of the first differential converter and the first Ethernet module is one;

[0014] The second end of the first Ethernet module is electrically connected to the second end of the second Ethernet module of the first slave communication device among the at least one slave communication device via the transmission cable, and the third end of the first Ethernet module is electrically connected to the last slave communication device among the at least one slave communication device via the transmission cable.

[0015] The third terminal of the second Ethernet module is electrically connected to the second terminal of the second Ethernet module of the second target communication device.

[0016] Preferably, the connection between the master communication device and the at least one slave communication device is a daisy-chain connection.

[0017] Preferably, the number of the first differential converter and the first Ethernet module is at least one;

[0018] The number of the host's SPI interface, the first differential converter, the first Ethernet module, and the slave communication devices are equal and correspond one-to-one;

[0019] Each of the SPI interfaces of the host is electrically connected to the first end of the corresponding first differential converter, the second end of the first differential converter is electrically connected to the first end of the corresponding first Ethernet module, the second end of the first Ethernet module is electrically connected to the second end of the corresponding second Ethernet module of the slave communication device through the transmission cable, and the third end of the first Ethernet module is left floating.

[0020] Preferably, the third end of the second Ethernet module of each of the communication devices is left floating.

[0021] Preferably, the transmission cable is a CAT5 or 8-core Ethernet cable.

[0022] Preferably, the first Ethernet module and the second Ethernet module are RJ45 Ethernet modules.

[0023] Preferably, the first differential converter and the second differential converter are RS485 differential converters.

[0024] This utility model has at least the following beneficial effects:

[0025] This application provides a high-speed differential synchronous bus communication circuit that utilizes a differential converter and an Ethernet module to achieve high-speed differential synchronous communication between a master communication device and slave communication devices. Compared with existing technologies, this invention effectively solves the limitations of traditional synchronous communication protocols under long-distance, high-bandwidth requirements. First, the use of differential signal transmission greatly improves anti-interference capability, enabling stable signal transmission in complex electromagnetic environments and solving the signal attenuation and quality degradation problems of existing synchronous communication methods over long distances. Second, the use of the Ethernet physical layer for transmission allows the system to support higher transmission bandwidth, while the use of CAT5 or higher specification transmission cables reduces the wiring difficulty and cost, and provides good scalability. By introducing an SPI interface, the master can correspond one-to-one with multiple slave communication devices, and the differential converter converts single-ended signals into differential signals. This design not only improves the data transmission rate but also effectively compensates for the shortcomings of existing solutions in terms of bandwidth and communication distance. Attached Figure Description

[0026] To more clearly illustrate the prior art and the present invention, the accompanying drawings used in the description of the prior art and the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are merely exemplary, and those skilled in the art can derive other drawings from the provided drawings without any creative effort.

[0027] The structures, proportions, sizes, etc. illustrated in this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed herein, and are not intended to limit the conditions under which this utility model can be implemented. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and purposes that this utility model can produce, should still fall within the scope of the technical content disclosed in this utility model.

[0028] Figure 1 A circuit block diagram of a high-speed differential synchronous bus communication circuit provided for an embodiment of this utility model.

[0029] Figure 2 A circuit block diagram of another high-speed differential synchronous bus communication circuit provided for an embodiment of this utility model.

[0030] Figure 3 A circuit diagram of a first differential converter or a second differential converter provided for embodiments of this utility model.

[0031] Figure 4 A circuit diagram of another first differential converter or a second differential converter provided for an embodiment of this utility model. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0033] In the description of this utility model, unless otherwise stated, "a plurality of" means two or more. The terms "first," "second," "third," "fourth," etc. (if present), in the specification, claims, and accompanying drawings of this utility model are intended to distinguish the objects they refer to. For solutions with a sequential flow, this terminology need not be interpreted as describing a specific order or sequence; for solutions with device structures, this terminology does not distinguish between matters of importance or positional relationships.

[0034] Furthermore, the terms “comprising,” “having,” and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are expressly listed, but may also include other steps or units that are not expressly listed but are inherent to these processes, methods, products, or devices, or steps or units added based on further optimizations of the inventive concept.

[0035] In one embodiment, such as Figure 1 and Figure 2 As shown, a high-speed differential synchronous bus communication circuit is provided. The circuit includes a master communication device and at least one slave communication device, as well as a transmission cable.

[0036] The main communication device includes a host, a first differential converter, and a first Ethernet module; the SPI interface of the host is electrically connected to a first terminal of the first differential converter, the second terminal of the first differential converter is electrically connected to a first terminal of the first Ethernet module, the second terminal of the first Ethernet module is electrically connected to the slave communication device, and the third terminal of the Ethernet module is either left floating or electrically connected to the last slave communication device among the at least one slave communication device.

[0037] For each of the slave communication devices, the slave communication device includes a slave unit, a second differential converter, and a second Ethernet module; the SPI interface of the slave unit is electrically connected to a first terminal of the second differential converter, the second terminal of the second differential converter is electrically connected to a first terminal of the second Ethernet module, and the second terminal of the second Ethernet module is electrically connected via the transmission cable to a second terminal of the first Ethernet module or a third terminal of the second Ethernet module of the first target slave communication device; the third terminal of the second Ethernet module is either left floating or electrically connected to a second terminal of the second Ethernet module of the second target slave communication device.

[0038] Wherein, the first target slave communication device is the preceding slave communication device among the at least one slave communication devices that is adjacent to the slave communication device; the second target slave communication device is the following slave communication device among the at least one slave communication devices that is adjacent to the slave communication device.

[0039] In this embodiment, the connection between the master communication device and the at least one slave communication device is a daisy-chain connection.

[0040] In this embodiment, the number of the first differential converter and the first Ethernet module is one;

[0041] The second end of the first Ethernet module is electrically connected to the second end of the second Ethernet module of the first slave communication device among the at least one slave communication device via the transmission cable, and the third end of the first Ethernet module is electrically connected to the last slave communication device among the at least one slave communication device via the transmission cable.

[0042] The third terminal of the second Ethernet module is electrically connected to the second terminal of the second Ethernet module of the second target communication device.

[0043] In this embodiment, the connection between the master communication device and the at least one slave communication device is a daisy-chain connection.

[0044] In this embodiment, the number of the first differential converter and the first Ethernet module is at least one;

[0045] The number of the host's SPI interface, the first differential converter, the first Ethernet module, and the slave communication devices are equal and correspond one-to-one;

[0046] Each of the SPI interfaces of the host is electrically connected to the first end of the corresponding first differential converter, the second end of the first differential converter is electrically connected to the first end of the corresponding first Ethernet module, the second end of the first Ethernet module is electrically connected to the second end of the corresponding second Ethernet module of the slave communication device through the transmission cable, and the third end of the first Ethernet module is left floating.

[0047] In this embodiment, the third end of the second Ethernet module of each of the slave communication devices is left floating.

[0048] In this embodiment, the transmission cable is a CAT5 or 8-core Ethernet cable.

[0049] In this embodiment, the first Ethernet module and the second Ethernet module are RJ45 Ethernet modules.

[0050] In this embodiment, the first differential converter and the second differential converter are RS485 differential converters.

[0051] In one embodiment, the existing RS485 bus can be driven without advanced peripherals, but its half-duplex communication mode cannot meet the high bandwidth requirements, with bandwidth mostly below 100kbps. A communication distance of 1000M is possible at a lower cost.

[0052] The CAN bus requires a dedicated peripheral driver for the communication chip, operates in full-duplex mode, and has a bandwidth typically below 1Mbps, but is relatively expensive. Its communication distance is 1000M. The Ethernet bus requires a dedicated PHY chip and advanced peripherals to drive it, necessitating a switch at the link layer. It also operates in full-duplex mode, with bandwidths reaching 100Mbps to 1000Mbps or even higher, but is extremely expensive. Its communication distance is around 100M. Synchronous communication methods are primarily SPI and IIC, using a single-ended voltage board-level communication protocol.

[0053] The SPI protocol requires four communication lines, does not require a dedicated PHY chip or advanced peripherals, and can achieve communication speeds of over 10Mbps or even 100Mbps. However, the communication distance is limited to 1M, and the transmission distance is also limited.

[0054] The IIC protocol requires two communication lines, does not require a dedicated PHY chip or advanced peripherals, and its communication speed is generally less than 1 Mbps. The communication distance is limited to no more than 1 meter.

[0055] like Figure 3 and Figure 4 As shown, the implementation scheme of this embodiment is as follows: The interface circuit uses an existing RS485 communication chip to convert single-ended signals into differential signals. The host side uses a differential converter with 3 transmitters and 1 receiver, and the receiver side uses a differential converter with 3 receivers and 1 transmitter. The physical layer can use Ethernet CAT5 or higher specification network cables, which can support daisy chain or daisy chain connection. The terminal receiver needs to use a 120Ω terminating resistor to avoid signal reflection and signal quality degradation. When selecting the slave address, multiple CS can be used to connect multiple slave RJ45 interfaces respectively when using daisy chain. When using daisy chain, each slave address can be set to distinguish the device address in software. ROREDE pull-up transmit state DI single-ended signal input A+B- differential signal output; DI pull-up REDE pull-down receive state RO data output A+B- differential signal input; when selecting differential converters, high-speed models can be used, or RS485 transceivers can be omitted. When connecting TVSESD and other protection devices to the differential end, pay attention to selecting low capacitive load devices, otherwise it is easy to cause the signal edge to be too slow, the signal distortion, and thus the communication failure. When the communication distance is long, it is necessary to reduce the frequency of the communication CLK clock signal or delay the reception of the input signal to compensate for the communication delay of the electrical signal synchronization.

[0056] like Figure 1 As shown, in the daisy-chain configuration, only one CS signal is needed to control all slave chip select signals, and master-slave communication can be achieved by agreeing in the software that the first byte is the slave device address.

[0057] The master SPI interface (CLKMOSIMISOCS) is converted into four differential signals (CLK+, CLK-, MOSI+, MOSI-, MISO+, MISO-, CS+, CS-) via a differential converter. CLKMOSICS is the output, and MISO is the input. A 120Ω terminating resistor is connected between MISO+ and MISO-. The four differential buses are brought out using an RJ45 Ethernet interface, with a CAT5 or higher specification 8-core Ethernet cable. The RJ45 interface of slave 1 is converted into a single-ended SPI signal via a differential converter for slave 1. Simultaneously, another Ethernet cable transmits the signal to slave 2 (bus terminator). A 120Ω terminating resistor is connected between CLK+CLK-, MOSI+MOSI-, and CS+CS- at the RJ45 interface to prevent signal reflection and reduce signal quality. The signal is then converted to a single-ended SPI signal by a differential converter for slave 2 to process. If the slave pulls the CS signal low, its starting address corresponds to the slave address, and the corresponding slave responds to the signal by sending back the MISO signal. This MISO signal is then transmitted back to the master via the RJ45 interface through the differential converter. After processing and parsing by the master, a complete communication process is completed. This process is for daisy-chain connections.

[0058] like Figure 2 As shown, in a daisy-chain configuration, each slave device requires a separate CS pin to control the master direction, which requires multiple CS control signals.

[0059] Before the SPI interface and differential converter, single-ended signal communication is used via the SPI interface. The master uses CLKMOSICS output and MISO input, while the slave uses CLKMOSICS input and MISO output. After passing through the differential converter, the SPI signal outputs four CLKMOSICSMISO differential signal pairs. These four differential signal pairs can be transmitted by connecting a CAT5 8-pin Ethernet cable via an RJ45 interface.

[0060] The host SPI interface CLKMOSIMISOCS is converted into four differential signals CLK+CLK-, MOSI+MOSI-, MISO+MISO-, CS1+CS1-, and CS2+CS2- via a differential converter. CLKMOSIMISOCS1 and CS2 are outputs, and MISO is the input. CS1 and CS2 are used individually (the number of CS channels depends on the number of slave devices), while CLKMOSIMISO is a shared channel for the host interface.

[0061] Taking a master-slave communication architecture as an example, the master uses two RJ45 interfaces, each sharing the CLKMOSIMISO channel, but the CS channel has independent CS1 and CS2 signals. The master's RJ45 interfaces are connected to the two slave ports using CAT5 or higher Ethernet cables. Each slave device's signal is converted to a single-ended SPI signal via its own differential converter for processing. If a slave's CS signal is pulled low, the signal processed by that slave is sent back to the master via the MISO channel after processing, and then sent back through the differential converter. After processing and parsing by the master, a complete communication cycle is completed. This process is for daisy-chain connections.

[0062] This solution uses RS485 level and Ethernet physical layer to transmit SPI signals, combining the advantages of multiple communication protocols. It has high transmission bandwidth, is simple and convenient to use, has good scalability, long transmission distance, strong anti-interference ability, and does not require the use of link equipment such as switches, thus reducing the cost of use. It achieves a balance between ease of use, transmission distance and bandwidth.

[0063] It utilizes the physical layer of existing mature protocols, uses an RS485 converter as a differential converter to reduce usage costs and is compatible with RS485 levels. It uses RJ45 standard interfaces and Ethernet cables as signal transmission media, which also reduces the difficulty of wiring and makes installation and use easier. It is also compatible with existing communication lines, reducing the cost of rewiring.

[0064] It supports multiple bus topologies. For daisy-chain configurations, simple hardware expansion is all that's needed for compatibility. For daisy-chain configurations, software differentiation is sufficient to achieve master-slave communication. The master and slave controllers also do not require advanced peripherals; in low-frequency applications, even I / O simulation can be used for communication.

[0065] The above specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0066] The technical features of the above embodiments can be combined in any way (as long as there is no contradiction in the combination of these technical features). For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described; these embodiments not explicitly written should also be considered to be within the scope of this specification.

[0067] The present invention has been described in a relatively specific and detailed manner above through general description and specific embodiments. It should be noted that, without departing from the concept of the present invention, various modifications and improvements can be made to these specific embodiments, all of which fall within the scope of protection of this application. Therefore, the scope of protection of this patent application should be determined by the appended claims.

Claims

1. A high-speed differential synchronous bus communication circuit, characterized in that, The circuit includes a master communication device and at least one slave communication device, as well as a transmission cable; The main communication device includes a host, a first differential converter, and a first Ethernet module; the SPI interface of the host is electrically connected to a first terminal of the first differential converter, the second terminal of the first differential converter is electrically connected to a first terminal of the first Ethernet module, the second terminal of the first Ethernet module is electrically connected to the slave communication device, and the third terminal of the Ethernet module is either left floating or electrically connected to the last slave communication device among the at least one slave communication device. For each of the slave communication devices, the slave communication device includes a slave unit, a second differential converter, and a second Ethernet module; the SPI interface of the slave unit is electrically connected to a first terminal of the second differential converter, the second terminal of the second differential converter is electrically connected to a first terminal of the second Ethernet module, and the second terminal of the second Ethernet module is electrically connected via the transmission cable to a second terminal of the first Ethernet module or a third terminal of the second Ethernet module of the first target slave communication device; the third terminal of the second Ethernet module is either left floating or electrically connected to a second terminal of the second Ethernet module of the second target slave communication device. Wherein, the first target slave communication device is the preceding slave communication device among the at least one slave communication devices that is adjacent to the slave communication device; the second target slave communication device is the following slave communication device among the at least one slave communication devices that is adjacent to the slave communication device.

2. The high-speed differential synchronous bus communication circuit according to claim 1, characterized in that, The connection between the master communication device and the at least one slave communication device is a daisy-chain connection.

3. The high-speed differential synchronous bus communication circuit according to claim 2, characterized in that, The number of the first differential converter and the first Ethernet module is one; The second end of the first Ethernet module is electrically connected to the second end of the second Ethernet module of the first slave communication device among the at least one slave communication device via the transmission cable, and the third end of the first Ethernet module is electrically connected to the last slave communication device among the at least one slave communication device via the transmission cable. The third terminal of the second Ethernet module is electrically connected to the second terminal of the second Ethernet module of the second target communication device.

4. The high-speed differential synchronous bus communication circuit according to claim 1, characterized in that, The connection between the master communication device and the at least one slave communication device is a daisy-chain connection.

5. A high-speed differential synchronous bus communication circuit according to claim 4, characterized in that, The number of the first differential converter and the first Ethernet module is at least one; The number of the host's SPI interface, the first differential converter, the first Ethernet module, and the slave communication devices are equal and correspond one-to-one; Each of the SPI interfaces of the host is electrically connected to the first end of the corresponding first differential converter, the second end of the first differential converter is electrically connected to the first end of the corresponding first Ethernet module, the second end of the first Ethernet module is electrically connected to the second end of the corresponding second Ethernet module of the slave communication device through the transmission cable, and the third end of the first Ethernet module is left floating.

6. A high-speed differential synchronous bus communication circuit according to claim 5, characterized in that, The third end of the second Ethernet module of each of the communication devices is left floating.

7. The high-speed differential synchronous bus communication circuit according to claim 1, characterized in that, The transmission cable is a CAT5 or 8-core Ethernet cable.

8. A high-speed differential synchronous bus communication circuit according to claim 1, characterized in that, The first Ethernet module and the second Ethernet module are RJ45 Ethernet modules.

9. A high-speed differential synchronous bus communication circuit according to claim 1, characterized in that, The first differential converter and the second differential converter are RS485 differential converters.

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