Communication system, relay device, and semiconductor device

Abstract

To provide a communication system capable of simultaneously controlling each relay device without using a counter.SOLUTION: In a communication system, a plurality of LED lighting devices 3 are cascaded to an LED lighting control device, and the LED lighting device 3 includes a first bypass wiring 8FS as a forward bypass from an upstream communication port SIOU to a downstream communication port SIOD, which is internally connected by a command "WDFS" from the LED lighting control device. When the command "WDFS" is received, the LED lighting device changes to the setting (RGB DUTY) instructed by the command "WDFS" and waits for execution, and also internally connects the forward bypass (first bypass wiring 8FS), and when a forward synchronization signal (command "FS") is received at the upstream communication port SIOU, the waiting setting (RGB DUTY) is executed.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] An embodiment of the present disclosure relates to a communication system in which a host and a plurality of relay devices cascaded in series to the host communicate serially. [Background technology]

[0002] An LED lighting system has been proposed in which a plurality of LED lighting devices that light up the LEDs are cascaded in series to an LED lighting control device that controls the lighting state of the LEDs (light emitting diodes), and the LED lighting control device and the plurality of LED lighting devices communicate serially (see, for example, Patent Document 1).

[0003] Such LED lighting systems have communication latency, so some kind of synchronization method is necessary to simultaneously control all the LEDs (turning them on / off, changing brightness or color). In Patent Document 1, a counter in each LED lighting device counts down from a counter start value that corresponds to the connection position, thereby synchronizing the times according to the communication latency and enabling simultaneous control of the LEDs. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2023-517657 Summary of the Invention [Problem to be solved by the invention]

[0005] However, time adjustment using a counter requires a complicated mechanism such as setting different count values ​​for each LED lighting device according to its connection position.

[0006] The present disclosure provides a communication system that can simultaneously control each relay device without using a counter. [Means for solving the problem]

[0007] The communication system of the present disclosure is a communication system in which a plurality of relay devices are cascade-connected to a host device, The relay device an upstream communication port for bidirectional communication with the host device in an upstream direction; a downstream communication port for bidirectional communication with the downstream side opposite to the host device; an upstream communication control device for communicating with the upstream communication port; a downstream communication control device for communicating with the downstream communication port; a control device that executes a command received by the upstream communication control device from the upstream communication port in the relay device, or that transmits a new command from the downstream communication port, or that transmits a new command from the upstream communication control device to the upstream communication port, or that executes a command received by the downstream communication control device from the downstream communication port in the relay device, or that transmits a new command from the upstream communication control device from the upstream communication port; a forward bypass that internally connects from the upstream communication port to the downstream communication port without passing through the upstream communication control device and the downstream communication control device, When the relay device receives a first command from the upstream communication port at the upstream communication control device, it internally connects the forward bypass, and when a second command is input to the upstream communication port, it outputs the command directly from the downstream communication port via the forward bypass. The present disclosure also provides a communication system in which a plurality of relay devices are cascade-connected to a host device, The relay device an upstream communication port for bidirectional communication with the host device in an upstream direction; a downstream communication port for bidirectional communication with the downstream side opposite to the host device; an upstream communication control device for communicating with the upstream communication port; a downstream communication control device for communicating with the downstream communication port; a control device that executes a command received by the upstream communication control device from the upstream communication port in the relay device, or that transmits a new command from the downstream communication port, or that transmits a new command from the upstream communication control device to the upstream communication port, or that executes a command received by the downstream communication control device from the downstream communication port in the relay device, or that transmits a new command from the upstream communication control device from the upstream communication port; a rear bypass that internally connects from the downstream communication port to the upstream communication port without passing through the downstream communication control device and the upstream communication control device; Equipped with When the relay device receives a fourth command from the upstream communication port at the upstream communication control device, it internally connects the rear bypass, and when a fifth command is input to the downstream communication port, it outputs the fifth command directly from the upstream communication port via the rear bypass. [Effects of the Invention]

[0008] The communication system of the present disclosure can simultaneously control each relay device without using a counter. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram showing a configuration of an embodiment of an LED lighting system. [Figure 2] 10A and 10B are diagrams illustrating examples of commands generated by the LED lighting control device. [Figure 3] FIG. 10 is a diagram illustrating an example of a packet. [Figure 4] FIG. 1 is a diagram illustrating a configuration of an LED lighting device. [Figure 5] FIG. 10 is a diagram illustrating a communication protocol for the command “INIT.” [Figure 6] FIG. 10 is a diagram illustrating a communication protocol for the command “WR.” [Figure 7] FIG. 1 is a diagram illustrating a "WRR" communication protocol. [Figure 8]FIG. 10 is a diagram illustrating a communication protocol for the commands “RR” and “RALL.” [Figure 9] FIG. 10 is a diagram illustrating a communication protocol for the command “WD.” [Figure 10] FIG. 10 is a diagram illustrating the communication protocols for the command "WDP" and the command "WDFS." [Figure 11] FIG. 10 is a diagram illustrating the communication protocols for the command "WDP" and the command "WDBS." DETAILED DESCRIPTION OF THE INVENTION

[0010] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings.

[0011] Referring to FIG. 1, the communication system 1 of this embodiment includes a plurality of LED lighting devices 3 that light up three RGB LEDs (hereinafter referred to as RGB-LEDs), and an LED lighting control device 2 that controls the lighting state of the LEDs of the plurality of LED lighting devices 3.

[0012] The LED lighting control device 2 and the multiple LED lighting devices 3 are cascade-connected via a communication line 10 for bidirectional 1-wire asynchronous serial communication, and commands are sent from the most upstream LED lighting control device 2 to the multiple downstream LED lighting devices 3 to control dimming, color adjustment, etc. In other words, the communication system 1 is a serial communication system, with the LED lighting control device 2 functioning as a host HOST and the LED lighting devices 3 functioning as relay device nodes.

[0013] The LED lighting control device 2 is an information processing device that operates under program control and has the function of generating various commands to control the LED lighting device 3. The LED lighting control device 2 includes an MCU (Micro Controller Unit) 21 that has a UART (Universal Asynchronous Receiver Transmitter) function. The LED lighting control device 2 includes a transmission terminal TXD and a reception terminal RXD. The MCU 21 transmits the generated command from the transmission terminal TXD to the downstream LED lighting device 3 via an open-drain buffer 22 in the form of a UART communication waveform shown in FIG. 2. The MCU 21 receives a response sent from the downstream LED lighting device 3 in the form of a UART communication waveform via the reception terminal RXD and buffer 23.

[0014] The LED lighting device 3 has an upstream communication port SIOU on the side closer to the LED lighting control device 2 and a downstream communication port SIOD on the side farther from the LED lighting control device 2, and both ports perform bidirectional 1-wire asynchronous serial communication.

[0015] Referring to FIG. 2, the types of commands generated by the LED lighting control device 2 are, for example, "INIT", "WR", "WRR", "RR", "RALL", "WD", "WDP", "WDFS", "WDBS", and "FS".

[0016] "INIT", "WR", "WRR", "RR", "RALL", "WD", "WDP", "WDFS", and "WDBS" are transmitted as a packet consisting of a rate adjustment byte and 64-bit data, as shown in Fig. 3. The 64-bit data of the packet includes "OPCODE" indicating the type of command, "LED_ADDR" which is address information specifying the LED lighting device 3, "PAYLOAD" where the data itself is stored, and "CRC8" which is an error detection code.

[0017] "INIT" is a command that sets the addresses of all connected LED lighting devices 3. The "LED_ADDR" of "INIT" can be any value (Any), and "PAYLOAD" stores the "LED_ADDR" that will be set for the LED lighting device 3 one level downstream, which will be the direct destination.

[0018] "WR" is a command that instructs the target LED lighting device 3 to write to a register inside the LED lighting device 3. "LED_ADDR" of "WR" is the address (Addr) of the target LED lighting device 3, and "PAYLOAD" stores the address (REG.A) of the register inside the LED lighting device 3 and the data (Data) to be written to that register.

[0019] "WRR" is a command that instructs the target LED lighting device 3 to write to a register inside the LED lighting device 3 and requests a response. "LED_ADDR" of "WRR" is the address (Addr) of the target LED lighting device 3, and "PAYLOAD" stores the address (REG.A) of the register inside the LED lighting device 3 and the data (Data) to be written to that register.

[0020] "RR" is a command that instructs the target LED lighting device 3 to read the register inside the LED lighting device 3 and requests a response. "LED_ADDR" in "RR" is the address (Addr) of the target LED lighting device 3, and "PAYLOAD" stores the address (REG.A) of the register inside the LED lighting device 3.

[0021] "RALL" is a command that instructs all LED lighting devices 3 to read their registers and requests a response. "LED_ADDR" in "RALL" can be any value (Any), and "PAYLOAD" stores the address (REG.A) of the register inside the LED lighting device 3 to be read.

[0022] "WD" is a command to set the dimming and color adjustment of the RGB-LED for the target LED lighting device 3. "LED_ADDR" is the address (Addr) of the target LED lighting device 3, and "PAYLOAD" stores the PWM duty (RGB DUTY) that drives each of the three RGB lights.

[0023] "WDP" is a command that temporarily stores the dimming and color adjustment of the RGB-LED in the target LED lighting device 3. "LED_ADDR" is the address (Addr) of the target LED lighting device 3, and "PAYLOAD" stores the PWM duty (RGB DUTY) that drives each of the three RGB lights. However, unlike "WD," with "WDP," the dimming and color adjustment setting values ​​are only set in the register, and the actual updating of the dimming and color adjustment of the RGB-LED is not executed and is put on hold. The actual updating of the dimming and color adjustment is executed when a forward synchronization signal or a backward synchronization signal is received after the forward synchronization mode or backward synchronization mode is set by the "WDFS" or "WDBS" command, which will be described later.

[0024] "WDFS" temporarily stores the RGB-LED dimming and color adjustment for the LED lighting device 3 specified by "LED_ADDR" while putting the execution on hold, and puts all LED lighting devices 3 that have received this command or received it and sent it downstream on hold in forward sync mode. Forward sync mode is a mode in which the settings that are on hold are executed by the command "FS" input as a forward sync signal to the upstream communication port SIOU. "LED_ADDR" in "WDFS" is the address (Addr) of the target LED lighting device 3, and "PAYLOAD" stores the PWM duty (RGB DUTY) that drives each of the three RGB lights.

[0025] "WDBS" is a command that temporarily stores the RGB-LED dimming and color adjustment settings for the LED lighting device 3 specified by "LED_ADDR" while putting the settings on hold. It also puts all LED lighting devices 3 that have received this command or that have received and sent it downstream into backward synchronization mode. Backward synchronization mode is a mode in which the standby settings are executed by the command "BS" input as a backward synchronization signal to the downstream communication port SIOD. When the most downstream node of a cascaded LED lighting device 3 receives "WDBS" from its upstream communication port SIOU, it sends the command "BS" back to the upstream side from its upstream communication port SIOU and simultaneously updates the dimming and color adjustment settings. "LED_ADDR" in "WDBS" is the address (Addr) of the target LED lighting device 3, and "PAYLOAD" stores the PWM duty (RGB DUTY) that drives each of the three RGB lights.

[0026] "FS" is a forward synchronization signal that instructs the LED lighting device 3, which is waiting in the forward synchronization mode, to execute the setting, and is composed only of the start bit of UART communication. "BS" is a backward synchronization signal that instructs the LED lighting device 3, which is waiting in the backward synchronization mode, to execute settings, and is composed only of the start bit of UART communication.

[0027] The LED lighting device 3 is an information processing device that operates under program control. The LED lighting device 3 can be configured as a semiconductor device such as an LSI, all or part of which is integrated on a substrate.

[0028] 4, the LED lighting device 3 includes an upstream communication control device 4 (hereinafter referred to as UTXRX4) having a UART function, and an upstream communication port SIOU to which a communication line 10 between the upstream LED lighting control device 2 or LED lighting device 3 is connected. The upstream communication port SIOU is connected to an input terminal of UTXRX4 via an upstream buffer 41. The LED lighting device 3 includes a downstream communication control device 5 (hereinafter referred to as DTXRX5) having a UART function, and a downstream communication port SIOD to which a communication line 10 between the downstream LED lighting device 3 is connected. The downstream communication port SIOD is connected to an input terminal of DTXRX5 via a downstream buffer 51.

[0029] The LED lighting device 3 includes a control unit 6 that controls the operation of the LED lighting device 3. The control unit 6 includes a control unit (CONTROL) 61, registers (Registers) 62, and a PWM signal generation unit 63 that generates PWM signals (dimming signals) for each of the three colors RGB. R , 63 G , 63 B In normal mode, if all nodes need to respond according to the "OPCODE" of the command received by UTXRX4, or if "LED_ADDR" is the device itself, the control unit 61 executes the operation instructed by the command. If the "LED_ADDR" of the command received by UTXRX4 is the address of another device (including other devices), the control unit 61 transmits (transfers) the command to the downstream LED lighting device 3 via DTXRX5. In addition, in the normal mode, the control unit 61 transmits and transfers the response packet received by the UTXRX5 from the downstream communication port SIOD in the upstream direction from the upstream communication port SIOU.

[0030] The register 62 is a storage unit that stores various setting information related to the operation of the LED lighting device 3. The register 62 stores various information, such as communication control information such as the device address and communication rate, lighting control information such as PWM (RGB DUTY) that drives each of the three RGB lights, and write / read control for eFuse, which stores LED brightness correction information in a non-volatile manner. The VPP terminal is a high voltage application terminal for writing to the eFuse.

[0031] PWM signal generation section 63 R , 63 G , 63 B The PWM signals of the PWM duty (RGB DUTY) stored in the register 62 are generated and output to the driver (DRV) 7. R , 7 G , 7 B Driver (DRV) 7 R , 7 G , 7 B The PWM signal generator 63 uses the DC voltage applied between the VCC terminal and the PGND terminal as a power supply. R , 63 G , 63 B The LED currents for the three RGB lights are generated according to the PWM signals generated by the register 62. The LED currents for the three RGB lights are output from the RED terminal, GRN terminal, and BLU terminal to which the LEDs of the three RGB lights are connected, and the three RGB lights are lit with the LED currents according to the PWM signals. In other words, the brightness and color of the three RGB lights are adjusted according to the PWM duty (RGB DUTY) of each of the three RGB lights stored in the register 62.

[0032] The LED lighting device 3 includes a downstream multiplexer 52 and a downstream open-drain buffer 53. The downstream multiplexer 52 has one input terminal connected to the output terminal of the upstream buffer 41 via a first bypass wiring 8. FSand the other input terminal is connected to the output terminal of DTXRX5. The output terminal of the downstream multiplexer 52 is connected to the downstream communication port SIOD via a downstream open-drain buffer 53. The downstream multiplexer 52 is an output selection circuit that selects whether the signal to be output from the downstream communication port SIOD is the output of the upstream buffer 41 or the output of DTXRX5.

[0033] The control unit 61 is normally set to normal mode. In normal mode, the control unit 61 outputs a forward synchronization selection signal FSMODE of low level "0" to the downstream multiplexer 52, thereby selecting the output of DTXRX5 as the signal to be output from the downstream communication port SIOD.

[0034] When the forward synchronization mode is set by the command "WDFS", the control unit 61 outputs a forward synchronization selection signal FSMODE of high level "1" to the downstream multiplexer 52, thereby selecting the output of the upstream buffer 41 as the signal to be output from the downstream communication port SIOD. That is, in the forward synchronization mode, the LED lighting device 3 selects the output of the upstream buffer 41 as the signal to be output from the downstream communication port SIOD through the communication path (first bypass wiring 8) from the upstream communication port SIOU to the downstream communication port SIOD. FS ) is logically internally connected as a forward bypass. Therefore, in forward synchronous mode, a signal input from the upstream communication port SIOU is output from the downstream communication port SIOD without causing communication latency.

[0035] The LED lighting device 3 includes an upstream multiplexer 42 and an upstream open-drain buffer 43. One input terminal of the upstream multiplexer 42 is connected to the output terminal of the downstream buffer 51 via a second bypass wiring 8. BSand the other input terminal is connected to the output terminal of UTXRX4. The output terminal of the upstream multiplexer 42 is connected to the upstream communication port SIOU via an upstream open-drain buffer 43. The upstream multiplexer 42 is an output selection circuit that selects whether the signal to be output from the upstream communication port SIOU is the output of the downstream buffer 51 or the output of UTXRX4.

[0036] The control unit 61 is normally set to normal mode. In normal mode, the control unit 61 outputs a backward synchronization selection signal BSMODE of low level “0” to the upstream multiplexer 42, thereby selecting the output of UTXRX4 as the signal to be output from the upstream communication port SIOU.

[0037] When the backward synchronization mode is set by the command "WDBS", the control unit 61 outputs a backward synchronization selection signal BSMODE of high level "1" to the upstream multiplexer 42, thereby selecting the output of the downstream buffer 51 as the signal to be output from the upstream communication port SIOU. That is, in the backward synchronization mode, the LED lighting device 3 selects the output of the downstream buffer 51 as the signal to be output from the upstream communication port SIOU through the communication path (second bypass wiring 8) from the downstream communication port SIOD to the upstream communication port SIOU. BS ) are logically internally connected as a backward bypass. Therefore, in backward synchronous mode, a signal input from the downstream communication port SIOD is output from the upstream communication port SIOU without causing communication latency.

[0038] 4, POR is a power-on reset circuit, OSC is an internal oscillator, LDO is a linear regulator, BG is a bandgap circuit, and TEMP is a temperature sensor. The voltages output by these are converted into digital values ​​by an ADC and input to a control unit 61.

[0039] Next, the communication protocol of the communication system 1 will be described in detail with reference to Figs. 5 to 11. In the following description, the number of LED lighting devices 3 cascade-connected to the LED lighting control device 2 will be five. The number of LED lighting devices 3 can be expanded to the range that can be specified by "LED_ADDR" in the command. Furthermore, the LED lighting control device 2 is the host HOST, and the addresses of the five LED lighting devices 3 cascade-connected to the LED lighting control device 2 will be RGB0 to RGB4 from the upstream side.

[0040] FIG. 5(a) shows the communication protocol for the command "INIT." The host HOST sets "LED_ADDR" to 0 and sends the command "INIT" downstream.

[0041] The LED lighting device 3 that receives the command "INIT" from the host HOST stores "LED_ADDR" in the register 62 as the address of its own device. Furthermore, to notify the upstream device of its existence, it sends a response "RES" with "OPCODE" of 0x01 upstream. At the same time, it sends a command "INIT" with "LED_ADDR" incremented (+1) to the downstream LED lighting device 3. As a result, the five LED lighting devices 3 are assigned addresses RGB0 to RGB4 from the upstream side, as shown in Figure 5(a). Note that the LED lighting device 3 that receives the response "RES" with "OPCODE" of 0x01 from downstream does not forward that response upstream.

[0042] In Figure 5(a), of the LED lighting devices 3, RGB4 does not receive a response "RES" with an "OPCODE" of 0x01 because there is no LED lighting device 3 downstream. For this reason, if RGB4 does not receive a response "RES" for a certain period of time, it recognizes that it is the last node and sends a response "RES" upstream with its own device address as the "LED_ADDR" and an "OPCODE" of 0x02. The LED lighting device 3 that receives a response with an "OPCODE" of 0x02 from the downstream side continues to forward it upstream. When the response "RES" with an "OPCODE" of 0x02 finally reaches the HOST, the HOST recognizes that the address assignment has been successful, and by looking at the "LED_ADDR" in that response "RES", it can determine the final address and number of cascaded LED lighting devices 3.

[0043] FIG. 5(b) shows the communication protocol when an error occurs during the transmission of the command "INIT." If an error occurs in the third LED lighting device 3 (RGB2), the third LED lighting device 3 will send an error response "Err" upstream with "OPCODE" set to 0x02, its own device's address (RGB2) set to "LED_ADDR," and a code containing the error details set to "PAYLOAD." The LED lighting device 3 that receives the response "Err" with "OPCODE" set to 0x02 from the downstream side will send the same response "Err" further upstream. As a result, the error response "Err" reaches the HOST, which then recognizes the location and content of the error. Note that in the communication protocol for the commands shown below, an LED lighting device 3 that detects an error will also send an "Err" response upstream with its own device's address set to "LED_ADDR" and a code containing the error details set to "PAYLOAD."

[0044] Figure 6 shows the communication protocol for the command "WR." In Figure 6, (a) shows an example of sending the command "WR" to one target device, and (b) shows an example of sending the command "WR" to multiple devices in succession. The host HOST sets the address (RGB2) of the target LED lighting device 3 to "LED_ADDR", generates a command "WR" that stores the address (REG.A) of the register in the LED lighting device 3 and the data (Data) to be written to the register in "PAYLOAD", and sends it downstream.

[0045] When the LED lighting device 3 receives the command "WR" from the host HOST, it references "LED_ADDR" to determine whether the command is addressed to itself or not, and if it is addressed to another device, it transmits the command "WR" further downstream. If the command "WR" is addressed to its own device, the LED lighting device 3 (RGB2) stores data (REG WR) at the specified address in the register 62 based on "PAYLOAD".

[0046] Figure 7 shows the communication protocol for the command "WRR." The communication protocol up to storing the data at the specified address in the register 62 is the same as for the command "WR." When the command "WRR" is addressed to its own device, the LED lighting device 3 (RGB2), referring to FIG. 2, generates a response "RES" with the same code as "WRR" in "OPCODE" and its own device address (RGB2) in "LED_ADDR" and sends it upstream. Upon receiving the response "RES" from the downstream side, the LED lighting device 3 sends the response "RES" further upstream. As a result, the response "RES" reaches the host HOST, which recognizes that the data has been successfully stored.

[0047] FIG. 8(a) shows the communication protocol for the command "RR." The host HOST generates a command "RR" in which "LED_ADDR" is the address (RGB2) of the target LED lighting device 3 and "PAYLOAD" is the address of the register (REG.A), and sends it downstream.

[0048] When the LED lighting device 3 receives the command "RR" from the host HOST, it references the "LED_ADDR" to determine whether the command is addressed to itself or not. If it is addressed to another device, it transmits the command "RR" further downstream. If the command "RR" is addressed to itself, the LED lighting device 3 (RGB2) reads the data stored in the specified address of the register 62 in the LED lighting device 3 based on the "PAYLOAD" (REG RD). Then, referring to FIG. 2, the LED lighting device 3 (RGB2) sets the "OPCODE" to the same code as "RR," sets the "LED_ADDR" to its own device address (RGB2), generates a response "DAT" with the read data in "PAYLOAD," and transmits it upstream. When the LED lighting device 3 receives the response "DAT" from the downstream side, it transmits the response "DAT" further upstream. As a result, the response "DAT" reaches the host HOST, and the host HOST can read the data stored in the register 62 of the target LED lighting device 3.

[0049] FIG. 8(b) shows the communication protocol for the command "RALL." The command "RALL" targets all LED lighting devices 3. The command "RALL" sent by the host HOST sets "LED_ADDR" to an arbitrary address (Any) and stores the register address (REG.A) in "PAYLOAD" before sending it downstream.

[0050] The LED lighting device 3 that received the command "RALL" from the host HOST recognizes by referencing the "OPCODE" that all LED lighting devices 3 (RGB0 to 4) are the target, and generates the response "DAT" described above and sends it upstream, while also sending the command "RALL" further downstream. As a result, the response "DAT" reaches the host HOST from all the LED lighting devices 3 (RGB0 to 4), and the host HOST can read the data stored in the registers 62 of all the LED lighting devices 3 (RGB0 to 4).

[0051] Figure 9 shows the communication protocol for the command "WD." The host HOST sets "LED_ADDR" to the address (Addr) of the target LED lighting device 3, generates a command "WD" that stores the PWM duty (RGB DUTY) to drive each of the three RGB lights in "PAYLOAD", and sends it downstream.

[0052] When the LED lighting device 3 receives the command "WD" from the host HOST, it determines whether it is addressed to itself or not, and if it is addressed to another device, it transmits the command "WD" further downstream. If the command "WD" is addressed to itself, the LED lighting device 3 stores the PWM duty (RGB DUTY) stored in "PAYLOAD" in register 62, thereby setting a change to the dimming and color adjustment of the RGB-LED and immediately executing the change to dimming and color adjustment. As a result, the dimming and color adjustment of the RGB-LED is updated and executed sequentially with a slight delay from the timing when the command "WD" is received.

[0053] Figure 10 shows the communication protocol for the "WDP" command and the "WDFS" command. The host HOST sets "LED_ADDR" to the address (Addr) of the target LED lighting device 3, generates a command "WDP" that stores the PWM duty (RGB DUTY) for driving each of the three RGB lights in "PAYLOAD", and sends it downstream.

[0054] When the LED lighting device 3 receives the command "WDP" from the host HOST, it determines whether it is addressed to itself or not, and if it is addressed to another device, it transmits the command "WDP" further downstream. If the command "WDP" is addressed to itself, the LED lighting device 3 writes the PWM duty (RGB DUTY) stored in "PAYLOAD" to the register 62 (Duty WD), stores it, and puts the update on hold (pending). The host HOST transmits the command "WDP" to all LED lighting devices 3 except the last node, stores the dimming and color adjustment settings for each LED, and puts the update on hold.

[0055] Next, the host HOST generates a command "WDFS" that stores the address (Addr) of the LED lighting device 3 of the final node in "LED_ADDR" and the duty (RGB DUTY) of each of the three RGB lights of the final node in "PAYLOAD", and sends it downstream.

[0056] The LED lighting device 3 that received the command "WDFS" from the host HOST determines whether it is addressed to itself or not, and if it is addressed to another device and not itself, transmits the command "WDFS" further downstream. If it is addressed to itself, it stores the duty (RGB DUTY) stored in "PAYLOAD" in the register 62, stores the RGB-LED dimming and color adjustment settings, and waits for the update to be executed. Furthermore, all LED lighting devices 3 that received the command "WDFS" or received and transferred it downstream transition to forward synchronization mode (FS-Mode). By transitioning to forward synchronization mode, the LED lighting device 3 that transferred the command "WDFS" outputs a forward synchronization selection signal FSMODE of high level "1" to the downstream multiplexer 52, thereby establishing a communication path (first bypass wiring 8) from the upstream communication port SIOU to the downstream communication port SIOD. FS ) is logically internally connected as a forward bypass. The signal (command "FS") input from the upstream communication port SIOU of the LED lighting device 3 that has transitioned to forward synchronous mode is output from the downstream communication port SIOD without any communication latency.

[0057] The host HOST waits until all LED lighting devices 3 (RGB0-4) have transitioned to forward synchronization mode, and then sends the command "FS" downstream as a forward synchronization signal. When the LED lighting devices 3 (RGB0-4) receive the forward synchronization signal (command "FS") in forward synchronization mode, they execute the settings they have been waiting for (updating the dimming and color adjustment of the RGB LEDs) and return to normal mode (N-Mode). Because the forward synchronization signal (command "FS") reaches the most downstream LED lighting device 3 (RGB4) without any communication latency, each LED lighting device 3 can simultaneously change to the dimming and color adjustment that was individually set, and the dimming and color adjustment of all LEDs changes simultaneously.

[0058] Figure 11 shows the communication protocol for the commands "WDP" and "WDBS." The host HOST sets "LED_ADDR" to the address (Addr) of the target LED lighting device 3, generates a command "WDP" that stores the PWM duty (RGB DUTY) for driving each of the three RGB lights in "PAYLOAD", and sends it downstream.

[0059] When the LED lighting device 3 receives the command "WDP" from the host HOST, it determines whether it is addressed to itself or not, and if it is addressed to another device, it sends the command "WDP" further downstream. If the command "WDP" is addressed to itself, the LED lighting device 3 writes the PWM duty (RGB DUTY) stored in "PAYLOAD" to the register 62 (Duty WD), stores the changes to the dimming and color adjustment of the RGB-LEDs, and puts the update on hold (pending). The host HOST sends the command "WDP" to all LED lighting devices 3 except the last node, stores the dimming and color adjustment settings for each LED, and puts the update on hold.

[0060] Next, the host HOST sets "LED_ADDR" to the address (Addr) of the LED lighting device 3 of the final node, and generates a command "WDBS" that stores the PWM duty (RGB DUTY) to drive each of the three RGB lights of the final node in "PAYLOAD", and sends it downstream.

[0061] When the LED lighting device 3 receives the "WDBS" command from the host HOST, it determines whether the command is addressed to itself. If it is addressed to another device, it sends the "WDFS" command further downstream. If the command is addressed to itself, it stores the PWM duty (RGB DUTY) stored in "PAYLOAD" in the register 62, storing the RGB LED dimming and color adjustment settings, and then waits for the update to be executed. Furthermore, all LED lighting devices 3 that have received the "WDBS" command or received and forwarded the command downstream transition to backward synchronization mode (BS-Mode). By transitioning to backward synchronization mode, the LED lighting device 3 that forwarded the "WDBS" command outputs a high-level "1" backward synchronization selection signal BSMODE to the upstream multiplexer 42, thereby logically internally wiring the communication path (second bypass wiring 8BS) from the downstream communication port SIOD to the upstream communication port SIOU as a backward bypass. The signal (command "BS") input from the downstream communication port SIOD of the LED lighting device 3 that has transitioned to the backward synchronization mode is output from the upstream communication port SIOU without causing communication latency.

[0062] The most downstream LED lighting device 3 (RGB4) that receives the command "WDBS" sends the command "BS" upstream as a backward synchronization signal, executes the settings it was waiting for (changing the dimming and color of the RGB-LEDs), and returns to normal mode (N-Mode). The other LED lighting devices 3 (RGB0-3) that receive the backward synchronization signal (command "BS") in backward synchronization mode execute the settings they were waiting for (updating the dimming and color of the RGB-LEDs) and return to normal mode (N-Mode). Because the backward synchronization signal (command "BS") reaches the most upstream LED lighting device 3 (RGB0) without any communication latency, each LED lighting device 3 can simultaneously change to the dimming and color settings that were individually set, and the dimming and color of all LEDs changes simultaneously. When the cascaded most downstream LED lighting device 3 receives the command "WDP" from the upstream communication port SIOU via TXDX4, it does not immediately execute the command (RGB DUTY) indicated by the command "WDP" but puts it on hold, and when it receives the command "WDBS" from the upstream communication port SIOU via TXDX4, it sends the command "BS" from the upstream communication port SIOU via TXDX4 and simultaneously executes the command that was put on hold by the command "WDP".

[0063] As described above, this embodiment relates to a communication system 1 in which a plurality of LED lighting devices 3 (relay devices) are cascade-connected to an LED lighting control device 2 (host device). The LED lighting device 3 includes an upstream communication port SIOU that communicates bidirectionally with the LED lighting control device 2 in the upstream direction, and a downstream communication port SIOD that communicates bidirectionally with the LED lighting control device 2 in the downstream direction. The LED lighting device 3 includes a TXDX4 (upstream communication control device) for communicating with the upstream communication port SIOU, and a TXDX5 (downstream communication control device) for communicating with the downstream communication port SIOD. The LED lighting device 3 includes a control device in which TXDX4 executes a command received from the upstream communication port SIOU within the LED lighting device 3, or TXDX5 transmits a new command from the downstream communication port SIOD, or transmits a new command from TXDX4 to the upstream communication port SIOU, or TXDX5 executes a command received from the downstream communication port SIOD within the LED lighting device 3, or TXDX4 transmits a new command from the upstream communication port SIOU. The LED lighting device 3 is provided with a forward bypass that internally connects from the upstream communication port SIOU to the downstream communication port SIOD without passing through TXDX4 and TXDX5. When the LED lighting device 3 receives a command "WDFS" (first command) from the upstream communication port SIOU via TXDX4, it internally connects the forward bypass, and when a command "FS" (second command) is input to the upstream communication port SIOU, it outputs the command directly from the downstream communication port SIOD via the forward bypass. In this embodiment, when the LED lighting device 3 receives the command "WDP" (third command) from the upstream communication port SIOU via TXDX4, it does not immediately execute the command (RGB DUTY) indicated by the command "WDP" but puts it on hold, and when it receives the command "WDFS" from the upstream communication port SIOU via TXDX4, it internally connects the forward bypass, and when the command "FS" is input to the upstream communication port SIOU, it outputs the command directly from the downstream communication port SIOD via the forward bypass, executes the command that was put on hold by the command "WDP", and releases the internal connection of the forward bypass. This configuration makes it possible to simultaneously control each LED lighting device 3 without using a counter. That is, the forward synchronization signal (command "FS") reaches the most downstream LED lighting device 3 (RGB4) without any communication latency, so each LED lighting device 3 can simultaneously change to the dimming and color adjustment that has been individually set, and the dimming and color adjustment of all LEDs changes simultaneously.

[0064] Furthermore, according to this embodiment, the LED lighting control device 2 waits for the timing when all of the cascaded LED lighting devices 3 suspend execution of the command "WDP," receive the next command "WDFS," and internally connect the forward bypasses, and then transmits the command "FS" downstream. This configuration allows the LED lighting control device 2 to determine the timing for executing the settings.

[0065] Moreover, this embodiment relates to a communication system 1 in which a plurality of LED lighting devices 3 (relay devices) are cascade-connected to an LED lighting control device 2 (host device), and the LED lighting device 3 includes an upstream communication port SIOU that communicates bidirectionally with the LED lighting control device 2 in the upstream direction, and a downstream communication port that communicates bidirectionally with the LED lighting control device 2 in the downstream direction. The LED lighting device 3 includes a TXDX4 (upstream communication control device) for communicating with the upstream communication port SIOU, and a TXDX5 (downstream communication control device) for communicating with the downstream communication port SIOD. The LED lighting device 3 includes a control device in which TXDX4 executes a command received from the upstream communication port SIOU within the LED lighting device 3, or TXDX5 transmits a new command from the downstream communication port SIOD, or transmits a new command from TXDX4 to the upstream communication port SIOU, or TXDX5 executes a command received from the downstream communication port SIOD within the LED lighting device 3, or TXDX4 transmits a new command from the upstream communication port SIOU. The LED lighting device 3 is provided with a rear bypass that internally connects from the downstream communication port SIOD to the upstream communication port SIOU without passing through TXDX5 and TXDX4. When the LED lighting device 3 receives the command "WDBS" (fourth command) from the upstream communication port SIOU via TXDX4, it internally connects the rear bypass, and when the command "BS" (fifth command) is input to the downstream communication port SIOD, it outputs the command directly from the upstream communication port SIOU via the rear bypass. In this embodiment, when the LED lighting device 3 receives the command "WDP" (sixth command) from the upstream communication port SIOU via TXDX4, it does not immediately execute the command (RGB DUTY) indicated by the command "WDP" but puts it on hold, and when it receives the command "WDBS" from the upstream communication port SIOU via TXDX4, it internally connects the rear bypass, and when the command "BS" is input to the downstream communication port SIOD, it outputs the command directly from the upstream communication port SIOU via the rear bypass, executes the command that was put on hold by the command "WDP", and releases the internal connection of the rear bypass. This configuration makes it possible to simultaneously control each LED lighting device 3 without using a counter. That is, the backward synchronization signal (command "BS") reaches the most upstream LED lighting device 3 (RGB0) without any communication latency, so each LED lighting device 3 can simultaneously change to its individually set dimming and color adjustment, and the dimming and color adjustment of all LEDs changes simultaneously.

[0066] Furthermore, according to this embodiment, when the cascaded most downstream LED lighting device 3 receives the command "WDP" from the upstream communication port SIOU via TXDX4, it does not immediately execute the command (RGB DUTY) indicated by the command "WDP" but puts it on hold, and when it receives the command "WDBS" from the upstream communication port SIOU via TXDX4, it sends the command "BS" from the upstream communication port SIOU via TXDX4 and simultaneously executes the command that was put on hold by the command "WDP". With this configuration, the LED lighting control device 2 can simultaneously control the dimming and color adjustment of all the LEDs without waiting for the timing at which all the LED lighting devices 3 wait to execute the setting (RGB DUTY).

[0067] It is clear that the present invention is not limited to the above-described embodiments, and that each embodiment can be appropriately modified within the scope of the technical concept of the present invention. Furthermore, the number, position, shape, etc. of the above-described components are not limited to the above-described embodiments, and the number, position, shape, etc. can be set to be suitable for implementing the present invention. Note that the same components are denoted by the same reference numerals in each drawing. [Explanation of symbols]

[0068] 1. Communication Systems 2 LED lighting control device 3 LED lighting device 4. Upstream communication control device 5 Downstream communication control device 6 Control Unit 8 BS Second bypass wiring 8 FS First bypass wiring 10 Communication lines 21 MCU 22 Open-drain buffer 23 buffers 41 Upstream buffer 42 Upstream Multiplexer 43 Upstream open-drain buffer 51 Downstream Buffer 52 Downstream Multiplexer 53 Downstream Open Drain Buffer 61 Control section 62 registers 63 R , 63 G , 63 B PWM signal generation section SIOD: Downstream communication port SIOU: Upstream communication port

Claims

1. A communication system in which a plurality of relay devices are cascade-connected to a host device, The relay device an upstream communication port for bidirectional communication with the host device in an upstream direction; a downstream communication port for bidirectional communication with the downstream side opposite to the host device; an upstream communication control device for communicating with the upstream communication port; a downstream communication control device for communicating with the downstream communication port; a control device that executes a command received by the upstream communication control device from the upstream communication port in the relay device, or that transmits a new command from the downstream communication port, or that transmits a new command from the upstream communication control device to the upstream communication port, or that executes a command received by the downstream communication control device from the downstream communication port in the relay device, or that transmits a new command from the upstream communication control device from the upstream communication port; a forward bypass that internally connects from the upstream communication port to the downstream communication port without passing through the upstream communication control device and the downstream communication control device, When the upstream communication control device receives a first command from the upstream communication port, the relay device internally connects the forward bypass, and when a second command is input to the upstream communication port, the second command is output from the downstream communication port via the forward bypass. A communication system comprising:

2. The relay device When the upstream communication control device receives a third command from the upstream communication port, the upstream communication control device does not immediately execute the command indicated by the third command but reserves it; When the first command is received by the upstream communication control device from the upstream communication port, the forward bypass is internally connected; When the second command is input to the upstream communication port, it is output as is from the downstream communication port via the forward bypass, and the command that was reserved in the third command is executed, and the internal connection of the forward bypass is released.

2. The communication system according to claim 1.

3. The host device transmits the second command downstream when all of the cascaded relay devices suspend execution of the third command, receive the first command, and internally connect the forward bypass.

3. The communication system according to claim 2.

4. A communication system in which a plurality of relay devices are cascade-connected to a host device, The relay device an upstream communication port for bidirectional communication with the host device in an upstream direction; a downstream communication port for bidirectional communication with the downstream side opposite to the host device; an upstream communication control device for communicating with the upstream communication port; a downstream communication control device for communicating with the downstream communication port; a control device that executes a command received by the upstream communication control device from the upstream communication port in the relay device, or that transmits a new command from the downstream communication port, or that transmits a new command from the upstream communication control device to the upstream communication port, or that executes a command received by the downstream communication control device from the downstream communication port in the relay device, or that transmits a new command from the upstream communication control device from the upstream communication port; a rear bypass that internally connects from the downstream communication port to the upstream communication port without passing through the downstream communication control device and the upstream communication control device; Equipped with When the upstream communication control device receives a fourth command from the upstream communication port, the relay device internally connects the rear bypass, and when a fifth command is input to the downstream communication port, the fifth command is output from the upstream communication port via the rear bypass. A communication system comprising:

5. The relay device When the sixth command is received by the upstream communication control device from the upstream communication port, the command indicated by the sixth command is not immediately executed but is reserved; when the fourth command is received by the upstream communication control device from the upstream communication port, internally connecting the rear bypass; When the fifth command is input to the downstream communication port, it is output as is from the upstream communication port via the rear bypass, and the command that was reserved in the sixth command is executed, and the internal connection of the rear bypass is released.

5. The communication system according to claim 4.

6. The most downstream relay device in the cascade connection When the sixth command is received by the upstream communication control device from the upstream communication port, the command indicated by the sixth command is not immediately executed but is reserved; When the fourth command is received by the upstream communication control device from the upstream communication port, The upstream communication control device transmits the fifth command from the upstream communication port, and at the same time executes the command that was reserved in the sixth command.

6. The communication system according to claim 5.

7. the relay device is an LED lighting device that lights up a plurality of LEDs, 5. The communication system according to claim 1, wherein the command instructs updating of the dimming and color adjustment of the plurality of LEDs.

8. A plurality of relay devices are cascade-connected to a host device, an upstream communication port for bidirectional communication with the host device in an upstream direction; a downstream communication port for bidirectional communication with the downstream side opposite to the host device; an upstream communication control device for communicating with the upstream communication port; a downstream communication control device for communicating with the downstream communication port; a control device that executes a command received by the upstream communication control device from the upstream communication port in the relay device, or that transmits a new command from the downstream communication port, or that transmits a new command from the upstream communication control device to the upstream communication port, or that executes a command received by the downstream communication control device from the downstream communication port in the relay device, or that transmits a new command from the upstream communication control device from the upstream communication port; a forward bypass that internally connects from the upstream communication port to the downstream communication port without passing through the upstream communication control device and the downstream communication control device, When the upstream communication control device receives a first command from the upstream communication port, the forward bypass is internally connected, and when a second command is input to the upstream communication port, the second command is output from the downstream communication port via the forward bypass. A relay device characterized by:

9. A plurality of relay devices are cascade-connected to a host device, an upstream communication port for bidirectional communication with the host device in an upstream direction; a downstream communication port for bidirectional communication with the downstream side opposite to the host device; an upstream communication control device for communicating with the upstream communication port; a downstream communication control device for communicating with the downstream communication port; a control device that executes a command received by the upstream communication control device from the upstream communication port in the relay device, or that transmits a new command from the downstream communication port, or that transmits a new command from the upstream communication control device to the upstream communication port, or that executes a command received by the downstream communication control device from the downstream communication port in the relay device, or that transmits a new command from the upstream communication control device from the upstream communication port; a rear bypass that internally connects from the downstream communication port to the upstream communication port without passing through the downstream communication control device and the upstream communication control device; Equipped with When the upstream communication control device receives a fourth command from the upstream communication port, the upstream communication control device internally connects the rear bypass, and when a fifth command is input to the downstream communication port, the fifth command is output from the upstream communication port via the rear bypass. A relay device characterized by:

10. 10. A semiconductor device comprising the relay device according to claim 8 or 9 integrated on a substrate.

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