Serial port communication circuit and electronic equipment

Abstract

The embodiment of the invention discloses a serial port communication circuit and electronic equipment, the serial port communication circuit comprises a first circuit and a second circuit, the first circuit is arranged on a first function board, and the second circuit is arranged on a second function board; the first end of the first circuit is connected with the first end of the second circuit through a first communication line, the second end and the third end of the first circuit are both connected with the first end of the first circuit, the second end is used for receiving a first signal, the third end is used for outputting a second signal, the fourth end is grounded, and the fifth end is used for accessing a first power supply; the fourth end of the first circuit is connected with the second end of the second circuit through a second communication line, the third end and the fourth end of the second circuit are both connected with the first end of the second circuit, the third end is used for receiving a second signal, the fourth end is used for outputting a first signal, the second end is grounded, and the fifth end is used for accessing a second power supply; the problem of high cost input can be solved, the number of communication lines between the two circuit boards is reduced, and the cost input is reduced.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of communication circuits, and in particular to a serial communication circuit and an electronic device. Background Art

[0002] Serial port communication is widely used in various electronic devices and circuit communications, such as display panels, main control boards, and frequency conversion boards of monitors.

[0003] The serial communication of existing display boards, main control boards or frequency conversion boards generally adopts half-duplex communication. Due to the overall structural design, the display board, main control board and frequency conversion board cannot be installed in the same position at the same time. They often need to be connected by long communication lines, and then the level conversion is performed through the communication conversion circuit in the circuit board. Therefore, the more data volume of the communication line between the two circuit boards, the higher the cost.

[0004] At least three communication lines are required between two existing circuit boards, namely a power line, a ground line and a transceiver line. The number of communication lines is large and the cost investment is high. Summary of the invention

[0005] The embodiments of the present application provide a serial communication circuit and electronic device, which can solve the problem of high cost investment, reduce the number of communication lines between two circuit boards, and reduce cost investment.

[0006] In a first aspect, an embodiment of the present application provides a serial communication circuit, including a first circuit and a second circuit, wherein the first circuit is arranged on a first functional board, and the second circuit is arranged on a second functional board;

[0007] The first end of the first circuit is connected to the first end of the second circuit through the first communication line, the second end and the third end of the first circuit are both connected to the first end of the first circuit, the fourth end of the first circuit is grounded, and the fifth end of the first circuit is used to connect to the first power supply;

[0008] The fourth end of the first circuit is connected to the second end of the second circuit through the second communication line, the third end and the fourth end of the second circuit are both connected to the first end of the second circuit, the second end of the second circuit is grounded, and the fifth end of the second circuit is used to connect to the second power supply;

[0009] receiving a first signal through the second end of the first circuit and transmitting the first signal to the first end of the first circuit; outputting the first signal through the first end of the first circuit and transmitting it to the first end of the second circuit via the first communication line; transmitting the received first signal to the fourth end of the second circuit through the first end of the second circuit, and outputting the first signal through the fourth end of the second circuit;

[0010] After the fourth end of the second circuit outputs the first signal, the second signal is received through the third end of the second circuit and the second signal is transmitted to the first end of the second circuit; the second signal is transmitted to the first end of the first circuit via the first communication line through the first end of the second circuit; the received second signal is transmitted to the third end of the first circuit through the first end of the first circuit, and the second signal is output through the third end of the first circuit.

[0011] In a second aspect, an embodiment of the present application provides an electronic device, comprising the serial port communication circuit described in the first aspect.

[0012] In the embodiment of the present application, the first circuit is arranged on the first functional board, and the second circuit is arranged on the second functional board, and the first circuit and the second circuit are communicatively connected through the first communication line and the second communication line. Compared with the existing system that requires at least three communication lines for communication connection, the number of communication lines is reduced, thereby solving the problem of high cost investment and reducing cost investment. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a first schematic diagram of a serial communication circuit provided in an embodiment of the present application;

[0014] Figure 2 is a second schematic diagram of a serial communication circuit provided in an embodiment of the present application;

[0015] Figure 3 is a schematic diagram of a first circuit of a serial communication circuit provided in an embodiment of the present application;

[0016] Figure 4 It is a schematic diagram of a second circuit of a serial communication circuit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical scheme and advantages of the present application clearer, the specific embodiments of the present application are further described in detail below in conjunction with the accompanying drawings. It is understood that the specific embodiments described herein are only used to explain the present application, rather than to limit the present application. It should also be noted that, for the convenience of description, only the part related to the present application but not all the contents are shown in the accompanying drawings. Before discussing the exemplary embodiments in more detail, it should be mentioned that some exemplary embodiments are described as processes or methods depicted as flow charts. Although the flow chart describes each operation (or step) as a sequential process, many of the operations therein can be implemented in parallel, concurrently or simultaneously. In addition, the order of each operation can be rearranged. The process can be terminated when its operation is completed, but it can also have additional steps not included in the accompanying drawings. The process can correspond to a method, a function, a procedure, a subroutine, a subprogram, etc.

[0018] The serial communication of existing circuit boards such as display boards, main control boards or frequency conversion boards generally adopts half-duplex communication. Due to the overall structural design, the display board, main control board and frequency conversion board generally cannot be installed in the same position at the same time, and often require a longer communication line to connect them, and then perform level conversion through the communication conversion circuit in the circuit board. Therefore, the more data volume of the communication line between the two circuit boards, the higher the cost. At least three communication lines are required between the existing two circuit boards, namely the power line, the ground line and the transceiver line. The number of communication lines is large, and the cost investment is high. Based on this, a serial communication circuit and an electronic device of an embodiment of the present application are provided to solve the problem of high cost investment of the existing serial communication circuit.

[0019] Figure 1 is a first schematic diagram of a serial communication circuit provided in an embodiment of the present application, referring to Figure 1 , the serial port circuit specifically includes a first circuit 1 and a second circuit 2, wherein the first circuit 1 is arranged on a first functional board 3, and the second circuit 2 is arranged on a second functional board 4. The first end of the first circuit 1 is connected to the first end of the second circuit 2 through a first communication line RX / TX, the second end and the third end of the first circuit 1 are both connected to the first end of the first circuit 1, the fourth end of the first circuit 1 is grounded, and the fifth end of the first circuit 1 is used to access the first power supply VCC1. The fourth end of the first circuit 1 is connected to the second end of the second circuit 2 through a second communication line GND, the third end and the fourth end of the second circuit 2 are both connected to the first end of the second circuit 2, the second end of the second circuit 2 is grounded, and the fifth end of the second circuit 2 is used to access the second power supply VCC2. The first signal is received through the second end of the first circuit 1 and transmitted to the first end of the first circuit 1; the first signal is output through the first end of the first circuit 1 and transmitted to the first end of the second circuit 2 via the first communication line RX / TX; the received first signal is transmitted to the fourth end of the second circuit 2 through the first end of the second circuit 2, and the first signal is output through the fourth end of the second circuit 2. After the fourth end of the second circuit 2 outputs the first signal, the second signal is received through the third end of the second circuit 2, and the second signal is transmitted to the first end of the second circuit 2; the second signal is transmitted to the first end of the first circuit 1 via the first communication line RX / TX through the first end of the second circuit 2; the received second signal is transmitted to the third end of the first circuit 1 through the first end of the first circuit 1, and the second signal is output through the third end of the first circuit 1.

[0020] It should be noted that the first signal and the second signal are communication signals. When the serial communication circuit in the embodiment of the present application is used in actual electronic products, the two functional boards are respectively installed or connected to an MCU (Microcontroller Unit), and the second end of the first circuit is connected to the communication port of the corresponding MCU, and the communication interface outputs a first signal for transmission to the second circuit, and is used to receive a second signal sent through the second circuit; the third end of the second circuit is connected to the communication interface of another corresponding MCU, and the communication interface outputs a second signal for transmission to the first circuit, and is used to receive a first signal sent through the first circuit.

[0021] It should be noted that the communication between the first function board 3 and the second function board 4 is a half-duplex communication mode.

[0022] As mentioned above, the fifth end of the first circuit 1 of the first functional board 3 is used to access the first power supply VCC1 to supply power to the first circuit 1 so as to maintain the normal operation of the first circuit 1. The fifth end of the second circuit 2 of the second functional board 4 is used to access the second power supply VCC2 so as to maintain the normal operation of the second circuit 2. Compared with the existing method of connecting two functional boards through a power communication line, the use of the power communication line is reduced while also reducing the transformer components set up due to the different voltages required by different functional boards, thereby reducing the cost investment of the power communication line and also reducing the cost of setting up the transformer components. The first functional board 3 and the second functional board 4 are connected for communication via the first communication line RX / TX and the second communication line GND. Compared with the existing method of requiring at least three communication lines for communication connection, the number of communication lines is reduced, thereby reducing the overall cost investment.

[0023] Figure 2 is a second schematic diagram of a serial communication circuit provided in an embodiment of the present application, Figure 3 is a schematic diagram of a first circuit of a serial communication circuit provided in an embodiment of the present application, with reference to Figure 2 and Figure 3, the first circuit 1 includes a first module 10, a voltage-stabilizing diode DZ1, and a second module 11. The first end of the first module 10 (i.e., pin 1 of the socket CN1 on the first functional board 3) is connected to the anode of the voltage-stabilizing diode DZ1 and to the first end of the second circuit 2 (i.e., pin 1 of the socket CN2 on the second functional board 4) through the first communication line RX / TX. The second end of the first module 10 is grounded, the third end of the first module 10 is used to access the first power supply VCC1, and the fourth end of the first module 10 (i.e., the TX1 end) is used to input the first signal. The first module 10 is used to receive the first signal through the fourth end, and output the first signal through the first end of the first module 10. After the first signal is output by the first end of the first module 10 (i.e., pin 1 of the socket CN1 on the first functional board 3), it is transmitted to the first end of the second circuit 2 (i.e., pin 1 of the socket CN2 on the second functional board 4) through the first communication line RX / TX, and the first signal is output through the fourth end of the second circuit 2 (i.e., the RX1 end). The first end of the second module 11 is connected to the cathode of the voltage zener diode DZ1, the second end of the second module 11 is grounded, the third end of the second module 11 is used to access the first power supply VCC1, and the fourth end of the second module 11 (i.e., the RX1 end) is used to output the second signal. The first circuit 1 receives the second signal sent by the second circuit 2 through the first communication line RX / TX, and the second signal is transmitted to the first end of the second module 11 through the voltage zener diode DZ1. The second module 11 transmits the second signal received from its first end to its fourth end, and outputs the second signal through its fourth end (i.e., the RX1 end).

[0024] The first module 10 includes a first amplifier unit 101 and a second amplifier unit 102. The first end of the first amplifier unit 101 is connected to the first end of the second amplifier unit 102, the second end of the first amplifier unit 101 is used to access the first power supply VCC1, and the third end of the first amplifier unit 101 (i.e., the TX1 end) is used to input the first signal. The second end of the second amplifier unit 102 is connected to the anode of the voltage-stabilizing diode DZ1 and the first end of the second circuit 2 through the first communication line RX / TX, the third end of the second amplifier unit 102 is used to access the first power supply VCC1, and the fourth end of the second amplifier unit 102 is grounded.

[0025] The first amplifying unit 101 includes a first resistor R1, a second resistor R2 and a first transistor Q1. The first end of the first resistor R1 is connected to the first end of the second resistor R2 and the base of the first transistor Q1, and the second end of the second resistor R2 (i.e., the TX1 end) is used to input the first signal. The second end of the first resistor R1 is connected to the emitter of the first transistor Q1, and the second end of the first resistor R1 is used to access the first power supply VCC1. The collector of the first transistor Q1 is connected to the first end of the second amplifying unit 102.

[0026] The second amplifying unit 102 includes a third resistor R3, a fourth resistor R4, a fifth resistor R5 and a second triode Q2. The first end of the third resistor R3 is connected to the first end of the first amplifying unit 101, and the second end of the third resistor R3 is connected to the first end of the fourth resistor R4 and the base of the second triode Q2. The second end of the fourth resistor R4 is connected to the emitter of the second triode Q2. The collector of the second triode Q2 is connected to the first end of the fifth resistor R5 and the first end of the second circuit 2 through the first communication line RX / TX, and the second end of the fifth resistor R5 is used to access the first power supply VCC1. The collector of the second triode Q2 is connected to the first end of the fifth resistor R5 and the anode of the voltage stabilizing diode DZ1, and is connected to the pin 1 of the socket CN1 of the first functional board 3. The pin 1 of the socket CN1 of the first functional board 3 is connected to the pin 1 of the socket CN2 of the second functional board 4 through the first communication line RX / TX.

[0027] The second module 11 includes a third amplifier unit 111 and a fourth amplifier unit 112. The first end of the third amplifier unit 111 is connected to the first end of the fourth amplifier unit 112, the second end of the third amplifier unit 111 is used to access the first power supply VCC1, the third end of the third amplifier unit 111 (i.e., the RX1 end) is used to output the second signal, and the fourth end of the third amplifier unit 111 is grounded. The second end of the fourth amplifier unit 112 is connected to the cathode of the voltage-stabilizing diode DZ1, and the third end of the fourth amplifier unit 112 is used to access the first power supply VCC1.

[0028] The third amplifying unit 111 includes a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a first capacitor C1 and a third triode Q3. The first end of the sixth resistor R6 is connected to the first end of the first capacitor C1, and the first end of the sixth resistor R6 (i.e., the RX1 end) is used to output the second signal. The second end of the sixth resistor R6 is connected to the first end of the seventh resistor R7 and the collector of the third triode Q3, and the second end of the seventh resistor R7 is used to access the first power supply VCC1. The base of the third triode Q3 is connected to the first end of the eighth resistor R8 and the first end of the ninth resistor R9. The second end of the eighth resistor R8 is grounded to the base of the third triode Q3 and the second end of the first capacitor C1. The second end of the ninth resistor R9 is connected to the first end of the fourth amplifying unit 112.

[0029] The fourth amplifier unit 112 includes a tenth resistor R10, an eleventh resistor R11 and a fourth triode Q4. The collector of the fourth triode Q4 is connected to the first end of the third amplifier unit 111. The base of the fourth triode Q4 is connected to the first end of the tenth resistor R10 and the first end of the eleventh resistor R11. The second end of the tenth resistor R10 is connected to the emitter of the fourth triode Q4, and the emitter of the fourth triode Q4 is used to access the first power supply VCC1. The second end of the eleventh resistor R11 is connected to the cathode of the voltage stabilizing diode DZ1.

[0030] Figure 4 is a schematic diagram of a second circuit of a serial communication circuit provided in an embodiment of the present application, referring to Figure 2 and Figure 4 , the second circuit 2 includes a third module 21, a fourth module 22, a fifth module 23, a sixth module 24 and a seventh module 25. The first end of the third module 21 is connected to the first end of the fourth module 22, the first end of the fifth module 23 and the first end of the first circuit 1 through the first communication line RX / TX, the second end of the third module 21 is connected to the second end of the first circuit 1 through the second communication line GND, and the second end of the third module 21 is grounded. The fourth end of the third module 21 is connected to the second end of the fourth module 22. The third end of the fourth module 22 is connected to the first end of the sixth module 24, and the fourth end of the fourth module 22 is used to access the second power supply VCC2; the second end of the sixth module 24 is used to access the second power supply VCC2, the third end of the sixth module 24 is used to ground, and the fourth end of the sixth module 24 (i.e., the RX2 end) is used to output the first signal. The second end of the fifth module 23 is connected to the first end of the seventh module 25, and the third end of the fifth module 23 is grounded; the second end of the seventh module 25 is used to access the second power supply VCC2, and the third end of the seventh module 25 (i.e., the TX2 end) is used to input the second signal.

[0031] The third module 21 includes a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14 and a fifth triode Q5. The first end of the twelfth resistor R12 is connected to the first end of the fourth module 22, the first end of the fifth module 23, the first end of the thirteenth resistor R13 and the first end of the first circuit 1 through the first communication line RX / TX. The first end of the twelfth resistor R12 is connected to the pin 1 of the socket CN2 of the second function board 4, and the pin 1 of the socket CN2 of the second function board 4 is connected to the pin 1 of the socket CN1 of the first function board 3 through the first communication line RX / TX. The second end of the twelfth resistor R12 is connected to the first end of the fourteenth resistor R14 and the base of the fifth triode Q5. The second end of the fourteenth resistor R14 is grounded to the emitter of the fifth triode Q5, and is connected to the second end of the second circuit 2 through the second communication line GND. The second end of the fourteenth resistor R14 is connected to the second end of the socket CN2 of the second functional board 4, the second end of the socket CN2 of the second functional board 4 is connected to the second end of the socket CN1 of the first functional board 3, and the second end of the socket CN1 of the first functional board 3 is grounded. The collector of the fifth transistor Q5 is connected to the second end of the thirteenth resistor R13 and the second end of the fourth module 22.

[0032] Pin 2 of socket CN1 of the first functional board 3 is connected to pin 2 of socket CN2 of the second functional board 4 through the second communication line GND, wherein pin 2 of socket CN1 of the first functional board 3 is grounded, and pin 2 of socket CN2 of the second functional board 4 is connected to the second end of the fourteenth resistor R14.

[0033] The fourth module 22 includes a fifteenth resistor R15, a sixteenth resistor R16 and a first optocoupler U1. The first end of the fifteenth resistor R15 is connected to the first end of the third module 21. The second end of the fifteenth resistor R15 is connected to the first end of the sixteenth resistor R16 and the positive electrode of the transmitter U1A of the first optocoupler U1. The second end of the sixteenth resistor R16 is connected to the negative electrode of the transmitter U1A of the first optocoupler U1 and the fourth end of the third module 21. The emitter of the receiving end U1B of the first optocoupler U1 is connected to the first end of the sixth module 24, and the collector of the receiving end U1B of the first optocoupler U1 is used to access the second power supply VCC2.

[0034] The fifth module 23 includes a second optical coupler U2, a seventeenth resistor R17 and an eighteenth resistor R18. The first end of the seventeenth resistor R17 is connected to the first end of the seventh module 25 and the positive electrode of the transmitter U2A of the second optical coupler U2. The second end of the seventeenth resistor R17 is connected to the first end of the eighteenth resistor R18 and the negative electrode of the transmitter U2A of the second optical coupler U2. The second end of the eighteenth resistor R18 is grounded. Among them, the second end of the eighteenth resistor R18 is connected to the protective ground (PGND) to achieve the effect of strong electrical isolation or weak electrical isolation, thereby protecting the circuit. The collector of the receiving end U2B of the second optical coupler U2 is connected to the first end of the third module 21, and the emitter of the receiving end U2B of the second optical coupler U2 is grounded.

[0035] The sixth module 24 includes a nineteenth resistor R19, a twentieth resistor R20, a twenty-first resistor R21, a twenty-second resistor R22, a second capacitor C2 and a sixth triode Q6. The first end of the nineteenth resistor R19 is connected to the third end of the fourth module 22. The second end of the nineteenth resistor R19 is connected to the first end of the twentieth resistor R20 and the base of the sixth triode Q6. The collector of the sixth triode Q6 is connected to the first end of the twenty-first resistor R21 and the first end of the twenty-second resistor R22, and the second end of the twenty-first resistor R21 is used to access the second power supply VCC2. The second end of the twenty-second resistor R22 is connected to the first end of the second capacitor C2, and the second end of the twenty-second resistor R22 (i.e., the RX2 end) is used to output the first signal. The second end of the twentieth resistor R20 is grounded to the emitter of the sixth triode Q6 and the second end of the second capacitor C2. Among them, the second end of the twentieth resistor R20 is connected to the protection ground (PGND) to achieve the effect of strong electrical isolation or weak electrical isolation, thereby protecting the circuit.

[0036] The seventh module 25 includes a seventh transistor Q7, a twenty-third resistor R23, and a twenty-fourth resistor R24. The collector of the seventh transistor Q7 is connected to the second end of the fifth module 23. The emitter of the seventh transistor Q7 is connected to the first end of the twenty-third resistor R23, and the emitter of the seventh transistor Q7 is used to access the second power supply VCC2. The base of the seventh transistor Q7 is connected to the second end of the twenty-third resistor R23 and the first end of the twenty-fourth resistor R24, and the second end (i.e., the TX2 end) of the twenty-fourth resistor R24 ​​is used to input the second signal.

[0037] The above-mentioned first circuit and second circuit communicate with each other through half-duplex communication mode, and it is determined through the communication protocol that when the second end (i.e., the TX1 end) of the second resistor R2 in the first circuit 1 sends a first signal, the second end (i.e., the RX2 end) of the twenty-second resistor R22 in the second circuit 2 will receive the first signal; when the second end (i.e., the TX2 end) of the twenty-fourth resistor R24 ​​in the second circuit 2 sends a second signal, the first end (i.e., the RX1 end) of the sixth resistor R6 in the first circuit 1 will receive the second signal.

[0038] In one embodiment, when the second end (i.e., the TX1 end) of the second resistor R2 in the first circuit 1 of the first functional board 3 inputs the first signal, that is, when data needs to be sent, the second end (i.e., the TX2 end) of the twenty-fourth resistor R24 ​​in the second circuit 2 of the second functional board 4 is at a high level, and the seventh transistor Q7 and the second optical coupler are not turned on. When the first signal inputted by the second end (i.e., the TX1 end) of the second resistor R2 in the first circuit 1 of the first functional board 3 is a high-level signal, that is, the second end (i.e., the TX1 end) of the second resistor R2 in the first circuit 1 of the first functional board 3 inputs a high-level signal, the first transistor Q1 is a PNP transistor, so the first transistor Q1 is not turned on, and then the second transistor Q2 is also not turned on. The current of the first power supply VCC1 is transmitted to the pin 1 of the socket CN2 of the second function board 4 through the fifth resistor R5, the pin 1 of the socket CN1 of the first function board 3, and the first communication line RX / TX, and is transmitted to the base of the fifth transistor Q5 through the twelfth resistor R12 as the driving signal of the fifth transistor Q5, so that the fifth transistor Q5 is turned on. Based on the conduction of the fifth transistor Q5, the first optical coupler U1 is also turned on, so that the current of the second power supply VCC2 drives the sixth transistor Q6 to be turned on through the receiving end U1 B of the first optical coupler U1. Due to the conduction of the sixth transistor Q6, the collector voltage of the sixth transistor Q6 is pulled down, so that the first signal output by the second end (i.e., the RX2 end) of the twenty-second resistor R22 in the second circuit 2 is a low-level signal. Therefore, when the first signal inputted from the second end (i.e., the TX1 end) of the second resistor R2 in the first circuit 1 of the first functional board 3 is a high level signal, the first signal outputted from the second end (i.e., the RX2 end) of the twenty-second resistor R22 in the second circuit 2 of the second functional board 4 is a low level signal.

[0039] In one embodiment, when the second end (i.e., the TX1 end) of the second resistor R2 in the first circuit 1 of the first functional board 3 inputs the first signal, that is, when data needs to be sent, the second end (i.e., the TX2 end) of the twenty-fourth resistor R24 ​​in the second circuit 2 of the second functional board 4 is at a high level, and the seventh transistor Q7 and the second optical coupler are not turned on. When the first signal inputted by the second end (i.e., the TX1 end) of the second resistor R2 in the first circuit 1 of the first functional board 3 is a low-level signal, the first transistor Q1 is a PNP-type transistor, so the first transistor Q1 is turned on, and then the second transistor Q2 is also turned on. Based on the conduction of the second transistor Q2, the collector of the second transistor Q2 is pulled down, so that the fifth transistor Q5 is not turned on, and then the first optical coupler U1 is not turned on, and the sixth transistor Q6 is not turned on, so that the voltage of the collector of the sixth transistor Q6 is high, so that the first signal outputted by the second end (i.e., the RX2 end) of the twenty-second resistor R22 in the second circuit 2 is a high-level signal. Therefore, when the first signal inputted from the second end (i.e., the TX1 end) of the second resistor R2 in the first circuit 1 of the first functional board 3 is a low level signal, the first signal outputted from the second end (i.e., the RX2 end) of the twenty-second resistor R22 in the second circuit 2 of the second functional board 4 is a high level signal.

[0040] As mentioned above, the first functional board 3 sends logic data (i.e., the first signal) through the second end (i.e., the TX1 end) of the second resistor R2, and the second functional board 4 can receive the corresponding logic data, that is, the second end (i.e., the RX2 end) of the twenty-second resistor R22 of the second functional board 4 receives the corresponding logic data (i.e., the first signal), thereby realizing communication between the first functional board 3 and the second functional board 4.

[0041] In one embodiment, when the second end (i.e., the TX2 end) of the twenty-fourth resistor R24 ​​in the second circuit 2 of the second functional board 4 inputs the second signal, that is, when data needs to be sent, the second end (i.e., the TX1 end) of the second resistor R2 in the first circuit 1 of the first functional board 3 is at a high level, and the first transistor Q1 and the second transistor Q2 are not turned on. When the second signal inputted by the second end (i.e., the TX2 end) of the twenty-fourth resistor R24 ​​in the second circuit 2 of the second functional board 4 is a high-level signal, since the seventh transistor Q7 is a PNP transistor, the seventh transistor Q7 is not turned on, and therefore the second optical coupler U2 is also not turned on. Since the second transistor Q2 and the second optical coupler U2 are not turned on, the first power supply VCC1 drives the fifth transistor Q5 through the fifth resistor R5 and the twelfth resistor R12, so that the fifth transistor Q5 is turned on. Assuming that the port voltage of the first communication line RX / TX is VBUS, it should be noted that the port voltage VBUS of the first communication line RX / TX can be changed by setting the resistance parameters of the fifth resistor R5, the twelfth resistor R12 and the thirteenth resistor R13. When the port voltage VBUS of the first communication line RX / TX plus the voltage of the voltage stabilizing diode DZ1 is greater than the voltage of the first power supply and the voltage between the emitter and the base of the fourth transistor Q4, that is, (VBUS+VDZ1)>(V1-VEB), the fourth transistor Q4 is not turned on. Wherein VDZ1 is the voltage of the voltage stabilizing diode, V1 is the voltage of the first power supply VCC1, and VEB is the voltage between the emitter and the base of the fourth transistor Q4. Since the fourth transistor Q4 is not turned on, the third transistor Q3 is also not turned on, so the collector of the third transistor Q3 is high level, so that the first end (ie, RX1 end) of the sixth resistor R6 in the first circuit 1 outputs a high level signal, that is, the output second signal is a high level signal. Therefore, when the second signal inputted from the second end (i.e., the TX2 end) of the twenty-fourth resistor R24 ​​in the second circuit 2 of the second functional board 4 is a high level signal, the second signal outputted from the first end (i.e., the RX1 end) of the sixth resistor R6 in the first circuit 1 of the first functional board 3 is a high level signal.

[0042] In one embodiment, when the second end (i.e., the TX2 end) of the 24th resistor R24 ​​in the second circuit 2 of the second functional board 4 inputs the second signal, that is, when data needs to be sent, the second end (i.e., the TX1 end) of the second resistor R2 in the first circuit 1 of the first functional board 3 is at a high level, and the first transistor Q1 and the second transistor Q2 are not turned on. When the second signal inputted by the second end (i.e., the TX2 end) of the 24th resistor R24 ​​in the second circuit 2 of the second functional board 4 is a low-level signal, since the seventh transistor Q7 is a PNP transistor, the seventh transistor Q7 is turned on, and therefore the second optical coupler U2 is also turned on. Due to the conduction of the second optical coupler U2, the voltage of the receiving end U2B of the second optical coupler U2 is pulled down, that is, the port voltage VBUS of the first communication line RX / TX is pulled down. At this time, when the port voltage VBUS of the first communication line RX / TX plus the voltage of the voltage-stabilizing diode DZ1 is less than the voltage of the first power supply and the voltage between the emitter and the base of the fourth transistor Q4, that is, (VBUS+VDZ1)<(V1-VEB), the fourth transistor Q4 is turned on. Wherein VDZ1 is the voltage of the voltage-stabilizing diode, V1 is the voltage of the first power supply VCC1, and VEB is the voltage between the emitter and the base of the fourth transistor Q4. Since the fourth transistor Q4 is turned on, the third transistor Q3 is also turned on, so the collector of the third transistor Q3 is at a low level, so that the first end (that is, the RX1 end) of the sixth resistor R6 in the first circuit 1 outputs a low-level signal, that is, the output second signal is a low-level signal. Therefore, when the second signal inputted from the second end (i.e., the TX2 end) of the twenty-fourth resistor R24 ​​in the second circuit 2 of the second functional board 4 is a low level signal, the second signal outputted from the first end (i.e., the RX1 end) of the sixth resistor R6 in the first circuit 1 of the first functional board 3 is a low level signal.

[0043] As mentioned above, the second end (i.e., the TX2 end) of the twenty-fourth resistor R24 ​​in the second circuit 2 of the second functional board 4 sends logic data (i.e., the second signal), and the first end (i.e., the RX1 end) of the sixth resistor R6 in the first circuit 1 of the first functional board 3 receives the corresponding logic data (i.e., the second signal), thereby realizing communication between the first functional board 3 and the second functional board 4.

[0044] As described above, the first circuit 1 of the first functional board 3 is connected to the first power supply VCC1 through the second end of the first resistor R1 and the first power supply VCC1 through the second end of the fifth resistor R5, so as to supply power to the first circuit 1 of the first functional board 3, and the first power supply VCC1 is connected through the second end of the seventh resistor R7 and the emitter of the fourth transistor Q4 to the first power supply VCC1 to realize the receiving and sending function of logic data (first signal or second signal). Compared with the existing method of connecting two functional boards through a power communication line, the use of the power communication line is reduced while also reducing the transformer components set for different voltages required for different functional boards, thereby reducing the cost investment of the power communication line and also reducing the cost of setting the transformer components. Similarly, the collector of the receiving end U1B of the first optical coupler U1 is connected to the second power supply VCC2, the second end of the twenty-first resistor R21 is connected to the second power supply VCC2, and the emitter of the seventh transistor Q7 is connected to the second power supply VCC2, so as to power the second circuit 2 of the second functional board 4 and help realize the receiving and sending function of the logic data (first signal or second signal). Compared with the existing method of connecting two functional boards through the power communication line, the use of the power communication line is reduced, and the transformer components set for different voltages required by different functional boards are also reduced, thereby reducing the cost investment of the power communication line and the cost of setting the transformer components. The first functional board 3 and the second functional board 4 are connected for communication through the first communication line RX / TX and the second communication line GND. Compared with the existing method of requiring at least three communication lines for communication connection, the number of communication lines is reduced, thereby reducing the overall cost investment.

[0045] In the above, the first circuit is set on the first functional board, the second circuit is set on the second functional board, and the first circuit and the second circuit are communicatively connected through the first communication line and the second communication line. Compared with the existing system that requires at least three communication lines for communication connection, the number of communication lines is reduced, thereby solving the problem of high cost investment and reducing cost investment.

[0046] On the basis of the above-mentioned embodiment, an embodiment of the present application further provides an electronic device, comprising the above-mentioned serial port communication circuit.

[0047] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0048] In this application, unless otherwise clearly specified and limited, the terms "set", "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0049] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0050] It should be noted that, in the present application, unless otherwise clearly specified and limited, the first feature being “above” or “below” the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being “above”, “above” and “above” the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the horizontal surface height of the first feature is higher than that of the second feature. The first feature being “below”, “below” and “below” the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the horizontal surface height of the first feature is lower than that of the second feature.

[0051] The above is only a preferred specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can make equivalent substitutions or changes within the technical scope disclosed in the present application according to the technical solution and application concept of the present application, which should be covered by the protection scope of the present application.

Claims

1. A serial communication circuit, characterized in that: It comprises a first circuit and a second circuit, wherein the first circuit is arranged on a first functional board, and the second circuit is arranged on a second functional board; The first end of the first circuit is connected to the first end of the second circuit through a first communication line, the second end and the third end of the first circuit are both connected to the first end of the first circuit, the fourth end of the first circuit is grounded, and the fifth end of the first circuit is used to connect to a first power supply; The fourth end of the first circuit is connected to the second end of the second circuit through the second communication line, the third end and the fourth end of the second circuit are both connected to the first end of the second circuit, the second end of the second circuit is grounded, and the fifth end of the second circuit is used to connect to the second power supply; receiving a first signal through the second end of the first circuit and transmitting the first signal to the first end of the first circuit; outputting the first signal through the first end of the first circuit and transmitting it to the first end of the second circuit via the first communication line; transmitting the received first signal to the fourth end of the second circuit through the first end of the second circuit and outputting the first signal through the fourth end of the second circuit; After the fourth end of the second circuit outputs the first signal, the second signal is received through the third end of the second circuit and the second signal is transmitted to the first end of the second circuit; the second signal is transmitted to the first end of the first circuit via the first communication line through the first end of the second circuit; the received second signal is transmitted to the third end of the first circuit through the first end of the first circuit, and the second signal is output through the third end of the first circuit.

2. The serial communication circuit according to claim 1, characterized in that: The first circuit includes a first module, a voltage stabilizing diode and a second module; The first end of the first module is connected to the anode of the voltage stabilizing diode and to the first end of the second circuit through the first communication line, the second end of the first module is grounded, the third end of the first module is used to connect to the first power supply, and the fourth end of the first module is used to input the first signal; The first end of the second module is connected to the cathode of the voltage-stabilizing diode, the second end of the second module is grounded, the third end of the second module is used to access the first power supply, and the fourth end of the second module is used to output a second signal.

3. The serial communication circuit according to claim 2, characterized in that: The first module includes a first amplification unit and a second amplification unit; The first end of the first amplifying unit is connected to the first end of the second amplifying unit, the second end of the first amplifying unit is used to connect to a first power supply, and the third end of the first amplifying unit is used to input a first signal; The second end of the second amplifying unit is connected to the anode of the voltage-stabilizing diode and to the first end of the second circuit via a first communication line. The third end of the second amplifying unit is used to access a first power supply. The fourth end of the second amplifying unit is grounded.

4. The serial communication circuit according to claim 3, characterized in that: The first amplifying unit includes a first resistor, a second resistor and a first transistor; The first end of the first resistor is connected to the first end of the second resistor and the base of the first transistor, and the second end of the second resistor is used to input a first signal; The second end of the first resistor is connected to the emitter of the first transistor, and the second end of the first resistor is used to connect to the first power supply; The collector of the first transistor is connected to the first end of the second amplifying unit.

5. The serial communication circuit according to claim 3, characterized in that: The second amplifying unit includes a third resistor, a fourth resistor, a fifth resistor and a second triode; The first end of the third resistor is connected to the first end of the first amplifying unit, and the second end of the third resistor is connected to the first end of the fourth resistor and the base of the second transistor; The second end of the fourth resistor and the emitter of the second transistor are grounded; The collector of the second transistor is connected to the first end of the fifth resistor and to the first end of the second circuit via a first communication line, and the second end of the fifth resistor is used to access the first power supply.

6. The serial communication circuit according to claim 2, characterized in that: The second module includes a third amplification unit and a fourth amplification unit; The first end of the third amplifying unit is connected to the first end of the fourth amplifying unit, the second end of the third amplifying unit is used to connect to the first power supply, the third end of the third amplifying unit is used to output the second signal, and the fourth end of the third amplifying unit is grounded; The second end of the fourth amplifying unit is connected to the cathode of the voltage stabilizing diode, and the third end of the fourth amplifying unit is used to access the first power supply.

7. The serial communication circuit according to claim 6, characterized in that: The third amplifying unit includes a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a first capacitor and a third triode; The first end of the sixth resistor is connected to the first end of the first capacitor, and the first end of the sixth resistor is used to output a second signal; The second end of the sixth resistor is connected to the first end of the seventh resistor and the collector of the third transistor, and the second end of the seventh resistor is used to connect to the first power supply; The base of the third transistor is connected to the first end of the eighth resistor and the first end of the ninth resistor; The second end of the eighth resistor, the base of the third transistor and the second end of the first capacitor are grounded; The second end of the ninth resistor is connected to the first end of the fourth amplifying unit.

8. The serial communication circuit according to claim 6, characterized in that: The fourth amplifying unit includes a tenth resistor, an eleventh resistor and a fourth triode; The collector of the fourth triode is connected to the first end of the third amplifying unit; The base of the fourth transistor is connected to the first end of the tenth resistor and the first end of the eleventh resistor; The second end of the tenth resistor is connected to the emitter of the fourth transistor, and the emitter of the fourth transistor is used to connect to the first power supply; The second end of the eleventh resistor is connected to the cathode of the voltage stabilizing diode.

9. The serial communication circuit according to claim 1, characterized in that: The second circuit includes a third module, a fourth module, a fifth module, a sixth module and a seventh module; The first end of the third module is connected to the first end of the fourth module, the first end of the fifth module and the first end of the first circuit through a first communication line, the second end of the third module is connected to the second end of the first circuit through a second communication line, and the second end of the third module is grounded; The fourth end of the third module is connected to the second end of the fourth module; The third end of the fourth module is connected to the first end of the sixth module, the fourth end of the fourth module is used to connect to the second power supply; the second end of the sixth module is used to connect to the second power supply, the third end of the sixth module is used to be grounded, and the fourth end of the sixth module is used to output the first signal; The second end of the fifth module is connected to the first end of the seventh module, and the third end of the fifth module is grounded; the second end of the seventh module is used to access a second power supply, and the third end of the seventh module is used to input a second signal.

10. The serial communication circuit according to claim 9, characterized in that: The third module includes a twelfth resistor, a thirteenth resistor, a fourteenth resistor and a fifth transistor; The first end of the twelfth resistor is connected to the first end of the fourth module, the first end of the fifth module, the first end of the thirteenth resistor, and the first end of the first circuit through the first communication line; The second end of the twelfth resistor is connected to the first end of the fourteenth resistor and the base of the fifth transistor; The second end of the fourteenth resistor is grounded to the emitter of the fifth transistor, and is connected to the second end of the second circuit via a second communication line; The collector of the fifth transistor is connected to the second end of the thirteenth resistor and the second end of the fourth module.

11. The serial communication circuit according to claim 9, characterized in that: The fourth module includes a fifteenth resistor, a sixteenth resistor and a first optical coupler; The first end of the fifteenth resistor is connected to the first end of the third module; The second end of the fifteenth resistor is connected to the first end of the sixteenth resistor and the positive electrode of the transmitting end of the first optical coupler; The second end of the sixteenth resistor is connected to the negative electrode of the transmitting end of the first optical coupler and the fourth end of the third module; The emitter of the receiving end of the first optical coupler is connected to the first end of the sixth module, and the collector of the receiving end of the first optical coupler is used to access the second power supply.

12. The serial communication circuit according to claim 9, characterized in that: The fifth module includes a second optical coupler, a seventeenth resistor and an eighteenth resistor; The first end of the seventeenth resistor is connected to the first end of the seventh module and the positive electrode of the transmitting end of the second optical coupler; The second end of the seventeenth resistor is connected to the first end of the eighteenth resistor and the negative electrode of the transmitting end of the second optical coupler; The second end of the eighteenth resistor is grounded; The collector of the receiving end of the second optical coupler is connected to the first end of the third module, and the emitter of the receiving end of the second optical coupler is grounded.

13. The serial communication circuit according to claim 9, characterized in that: The sixth module includes a nineteenth resistor, a twentieth resistor, a twenty-first resistor, a twenty-second resistor, a second capacitor and a sixth transistor; The first end of the nineteenth resistor is connected to the third end of the fourth module; The second end of the nineteenth resistor is connected to the first end of the twentieth resistor and the base of the sixth transistor; The collector of the sixth transistor is connected to the first end of the twenty-first resistor and the first end of the twenty-second resistor, and the second end of the twenty-first resistor is used to connect to the second power supply; The second end of the 22nd resistor is connected to the first end of the second capacitor, and the second end of the 22nd resistor is used to output the first signal; A second end of the twentieth resistor, an emitter of the sixth transistor, and a second end of the second capacitor are grounded.

14. The serial communication circuit according to claim 9, characterized in that: The seventh module includes a seventh transistor, a twenty-third resistor and a twenty-fourth resistor; The collector of the seventh triode is connected to the second end of the fifth module; The emitter of the seventh triode is connected to the first end of the twenty-third resistor, and the emitter of the seventh triode is used to connect to the second power supply; The base of the seventh transistor is connected to the second end of the twenty-third resistor and the first end of the twenty-fourth resistor, and the second end of the twenty-fourth resistor is used to input the second signal.

15. An electronic device, characterized in that: Comprising the serial communication circuit described in any one of claims 1-14.

Images