Synchronous circuit for single-wire transmission

Abstract

The invention discloses a single-wire transmission synchronous circuit, which is characterized in that a plurality of chips are connected in a single-wire manner, a plurality of coherent brightness control instructions are transmitted to the plurality of chips, and the plurality of coherent brightness control instructions are transmitted among the plurality of chips in the single-wire manner; each chip takes out a corresponding brightness control instruction from a plurality of coherent brightness control instructions, and the rest brightness control instructions continue to be transmitted to the next chip; each chip starts counting after obtaining the corresponding brightness control instruction; when the maximum bolt locking time is counted, the chip receives a synchronous signal; and after all the chips receive the synchronization signal, the LED brightness is synchronously updated by using a brightness adjustment parameter in the corresponding instruction.

Description

[0001] This application is a divisional application of the invention patent application with application number 202411207874.4. The filing date of the original application is August 30, 2024. Technical Field

[0002] The invention relates to a single-line transmission technology, in particular to a circuit for realizing synchronous update of LED brightness in a single-line transmission mode. Background Art

[0003] See also Figure 1 , is a single-line circuit wiring diagram of a traditional single chip. Figure 1 As shown, chip 11 is an integrated circuit (IC) for driving the LED (such as LED chip) in the display device to emit light, which includes an input terminal (DIN) and an output terminal (DOUT). Chip 11 outputs current to the LED, and controls the LED to emit different brightness according to the different output current sizes. Through a specific transmission protocol, chip 11 will be able to receive brightness adjustment parameters through DIN. After chip 11 obtains the brightness adjustment parameters, it will adjust the output current size according to the brightness adjustment parameters to update the LED brightness (LED Brightness).

[0004] See also Figure 2 , is a schematic diagram of a traditional single chip transmitting instructions in a single-line manner. Figure 1 and Figure 2 As shown, the chip 11 is preset with a latch time (LATCH_TIME) 111. When the chip 11 receives a CMD (Command) including a brightness adjustment parameter through DIN, it will count a latch time (LATCH_TIME) 111. As long as this latch time (LATCH_TIME) 111 lasts, the potential of DIN is always maintained at a low level state (L), which means that the CMD input from DIN has been transmitted. At this time, the chip 11 adjusts the output current according to the brightness adjustment parameter in the CMD.

[0005] See also Figure 3 , is a traditional single-line circuit wiring diagram of multiple chips. Figure 3 As shown, multiple chips (IC1~IC N )11 are connected in series, and the DOUT of the previous chip 11 will be used as the DIN of the next chip 11, so the chips 11 and 11 are connected only by a single line. The information transmitted by a host is input through the DIN of the first chip (IC1) 11 and passes through the chips (IC1~IC N-1 )11DOUT1~DOUT N-1 Transmit in sequence to the last chip (ICN )11.

[0006] See also Figure 4 , is a schematic diagram of the traditional single-line transmission results of multiple chips. Figure 3 and Figure 4 As shown, when there are N chips (IC1~IC N )11CMD S When transmission is required, the host will send N consecutive CMDs. S Each chip 11 receives a continuous CMD signal through DIN. S After that, from the coherent CMD S Take out the corresponding CMD, and the remaining CMD S Transmitted through DOUT. When N consecutive CMD S After all the signals are sent, the potential of DIN is maintained at a low level (L). After each chip 11 counts the latch time (LATCH_TIME) 111, it updates the brightness of the LED according to the brightness adjustment parameter received in the CMD.

[0007] However, due to the variation in semiconductor manufacturing process, the internal frequency of each chip 11 may be different. Therefore, even if the same latch time (LATCH_TIME) 111 is preset for each chip 11, the actual counted latch time (LATCH_TIME) 111 is not consistent. For example, the latch time (LATCH_TIME_1) counted by IC1 is T3, the latch time (LATCH_TIME_2) counted by IC2 is T1, and the latch time (LATCH_TIME_3) counted by IC3 is T2. N The length of the latch time (LATCH_TIME_N) counted is T4. Since the length of the latch time (LATCH_TIME) 111 actually counted by each chip 11 is not consistent, the time point for each chip 11 to update the LED brightness will be different, which will cause the display quality of the display device to decrease. Summary of the invention

[0008] One purpose of the present invention is to propose an innovative single-line transmission synchronization method, which connects multiple chips in a single-line manner, transmits multiple consecutive brightness control instructions to the multiple chips, and transmits the multiple consecutive brightness control instructions between the multiple chips in a single-line manner; each chip takes out at least one corresponding brightness control instruction from the multiple consecutive brightness control instructions and continues to transmit the remaining brightness control instructions to the next chip; furthermore, since the chip will cause an error in the internal frequency due to process variation, the latch time originally preset for each chip is inconsistent, resulting in the inability to synchronously update the brightness of the LED; therefore, in order to improve the problem that the LED brightness cannot be updated synchronously, the chip of the present invention will set a maximum latch time by summing the preset latch time and the maximum error value of the chip's internal frequency; each chip starts counting after obtaining the corresponding brightness control instruction; when counting reaches the maximum latch time, the chip will receive a synchronization signal; after receiving the synchronization signal, all chips will synchronously update the LED brightness by using a brightness adjustment parameter in the corresponding brightness control instruction. In this way, the brightness of LEDs in the display device can be updated synchronously to improve the display quality of the display device.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions:

[0010] To achieve the above-mentioned purpose, the present invention provides a single-wire transmission synchronization method, characterized in that it includes: connecting multiple chips with a single wire; transmitting multiple consecutive instructions to multiple chips; transmitting multiple consecutive instructions between multiple chips with a single wire and each chip taking out at least one corresponding instruction from the multiple consecutive instructions and continuing to transmit the remaining instructions to the next chip; allowing each chip to start counting after obtaining the corresponding instruction; allowing each chip to receive a synchronization signal after counting to a maximum value latch time; allowing all chips to synchronously update LED brightness with a brightness adjustment parameter in the corresponding instruction after receiving the synchronization signal.

[0011] Preferably, the single-wire transmission synchronization method further comprises: setting a preset latching time in each chip; and summing up the preset latching time and a maximum internal frequency error value of a chip to determine a maximum latching time.

[0012] Preferably, the single-wire transmission synchronization method further comprises: controlling the chip to control the magnitude of the output current with a brightness adjustment parameter in the corresponding instruction to update the brightness of the LED.

[0013] In addition, the present invention provides a single-line transmission synchronization circuit, characterized in that it includes: multiple chips, multiple chips are connected in a single-line manner, multiple consecutive brightness control instructions are transmitted to the multiple chips, and the multiple consecutive brightness control instructions are transmitted between the multiple chips in a single-line manner. Each chip takes out at least one corresponding brightness control instruction from the multiple consecutive brightness control instructions and the remaining brightness control instructions continue to be transmitted to the next chip; wherein each chip includes an input end and an output end, and its circuit structure includes: a counter connected to the input end and set with a maximum latch time; a switch; a synchronization signal receiver connected to the input end, the counter and the switch; a first data latch connected to the input end and a switch, receiving a corresponding brightness control instruction from an input end and storing the corresponding brightness control instruction; a second data latch, connected to the switch; and an LED driver, connected to the second data latch and the output end; wherein, when each chip obtains the corresponding brightness control instruction, the counter starts counting; when the counter counts to a maximum latch time, the synchronization signal receiver receives a synchronization signal and controls the switch to conduct the line between the first data latch and the second data latch, so as to update the corresponding brightness control instruction stored in the first data latch to the second data latch, and the LED driver obtains the corresponding brightness control instruction from the data latch and updates the brightness of the LED according to the corresponding brightness control instruction.

[0014] Preferably, the counter is further set with a preset latching time, and the maximum latching time is the sum of the preset latching time and the maximum error value of the internal frequency of a chip.

[0015] Preferably, the brightness control instruction includes a brightness adjustment parameter, and the LED driver controls the magnitude of the output current according to the brightness adjustment parameter of the brightness control instruction to update the brightness of the LED.

[0016] The technical advantage of the present invention is that each chip is connected in a single-line manner, and a maximum latch time is set in each chip. When each chip receives a brightness control instruction, it will count to the maximum latch time, and after receiving a synchronization signal, all chips will update the LED brightness according to the brightness control instruction, which will achieve the purpose of changing the LED brightness at the same time, thereby improving the display quality of the display device. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is the single-line circuit wiring diagram of a traditional single chip.

[0018] Figure 2 A schematic diagram of a traditional single chip transmitting instructions in a single-line manner.

[0019] Figure 3 This is a single-line circuit wiring diagram for traditional multiple chips.

[0020] Figure 4 This is a schematic diagram of the traditional single-line transmission results of multiple chips.

[0021] Figure 5 This is a single-line circuit wiring diagram of a single chip of the present invention.

[0022] Figure 6 It is a schematic diagram of a single chip transmitting instructions in a single-line manner according to the present invention.

[0023] Figure 7 FIG. 4 is a circuit architecture diagram of the chip of the present invention.

[0024] Figure 8 This is a single-line circuit wiring diagram of multiple chips of the present invention.

[0025] Fig. 9 It is a schematic diagram of the single-line transmission results of multiple chips of the present invention.

[0026] Description of Reference Numerals

[0027] 11: Chip

[0028] 31: Chip

[0029] 311: Counter

[0030] 312: Synchronous signal receiver

[0031] 313: First data latch

[0032] 314: Switch

[0033] 315: Second data latch

[0034] 316: LED Driver DETAILED DESCRIPTION

[0035] In order to make the objects, features and advantages of the present invention more obvious and easy to understand, the present application is further described in detail below in conjunction with drawings and specific implementation methods.

[0036] See also Figure 5 , Figure 6 and Figure 7 , respectively, are a single-line circuit wiring diagram of a single chip of the present invention, a schematic diagram of a single chip of the present invention transmitting instructions in a single-line manner, and a circuit architecture diagram of the chip of the present invention. Figure 5 , Figure 6 and Figure 7 As shown, the chip 31 of the present invention is an IC for driving the LED (such as LED crystal) in the display device to emit light, and it can control the LED to emit different brightness according to different output current sizes.

[0037] like Figure 7As shown, the chip 31 includes an input terminal (DIN) and an output terminal (DOUT), and its circuit structure includes a counter 311, a synchronous signal receiver 312, a first data latch 313, a switch 314, a second data latch 315 and an LED driver 316. The counter 311 is connected to the input terminal (DIN) and the synchronous signal receiver 312. The synchronous signal receiver 312 is connected to the input terminal (DIN), the counter 311 and the switch 314. The first data latch 313 is connected to the input terminal (DIN) and the switch 314. The switch 314 is connected between the synchronous signal receiver 312, the first data latch 313 and the second data latch 315. The second data latch 315 is connected to the switch 314 and the LED driver 316. The LED driver 316 is connected to the second data latch 315 and the output terminal (DOUT).

[0038] like Figure 5 , Figure 6 and Figure 7 As shown, in the process of updating the LED brightness of this embodiment, first, the host transmits a brightness control command (CMD) including brightness adjustment parameters to the chip 31. After the chip 31 receives the CMD through DIN, it latches the CMD in the first data latch 313 and counts through the counter 311. After the counter 311 counts to the preset latch time (PRE_LATCH_TIME) 311, the host sends a synchronization signal (SYNC Signal) to the chip 31 in the next step. After the synchronization signal receiver 312 of the chip 31 receives the synchronization signal (SYNC Signal) through DIN, it controls the switch 314 to conduct the line between the first data latch 313 and the second data latch 315, so that the CMD stored in the first data latch 313 is updated to the second data latch 315. After that, the second data latch 315 sends the CMD to the LED driver 316, and the LED driver 316 controls the output current according to the brightness adjustment parameters in the CMD, thereby updating the brightness of the LED.

[0039] See also Figure 8 and Fig. 9 , respectively, are the single-line circuit wiring diagram of multiple chips of the present invention and the single-line transmission result schematic diagram of multiple chips of the present invention. Figure 8 As shown, multiple chips (IC1~IC N )31 are connected in series, and the DOUT of the previous chip 31 will serve as the DIN of the next chip 31, so the chips 31 are connected to each other only through a single line.

[0040] like Figure 8 and Fig. 9 As shown, when there are N chips (IC1~IC N)31CMD S When transmission is required, the host will send N consecutive CMDs. S Each chip 31 receives a continuous CMD signal through DIN. S After that, from the coherent CMD S Take out the corresponding CMD, and the remaining CMD S Continue to transmit through DOUT to the last chip (IC N ) 31. Then, the CMD is transmitted to the corresponding chips 31 by a single-line transmission method.

[0041] In order to synchronize the LED brightness of each chip 31, each chip 31 includes a preset latch time (PRE_LATCH_TIME) 311. When the chip 31 receives a CMD containing a brightness adjustment parameter through DIN, it will count a preset latch time (PRE_LATCH_TIME) 311. When the chip 31 counts the preset latch time (PRE_LATCH_TIME) 311 and receives the synchronization signal, the chip 31 will change the output current according to the brightness adjustment parameter in the received CMD. However, this approach essentially cannot achieve the purpose of synchronously updating the LED brightness. The reason is that due to the variation of the semiconductor process, the actual internal frequency of each chip 31 produced by the process has an error with the original specified internal frequency. For example, the chip internal frequency designed according to the original specification is 10us, and the factors of semiconductor process variation will produce an internal frequency error (such as + / -1us), so that the actual internal frequency of the chip 31 produced by the process may fall within the range of 9us to 11us, resulting in the preset latch time (PRE_LATCH_TIME) 311 of each chip 31 being inconsistent, and ultimately the purpose of synchronously updating the LED brightness cannot be achieved.

[0042] Here, in order to avoid the situation that the time for each chip 31 to update the LED brightness is inconsistent, each chip 31 of the present invention further sets a maximum latch time (MAX_LATCH_TIME) 312. The maximum latch time (MAX_LATCH_TIME) 312 is formulated as the sum of an internal frequency maximum error value and a preset latch time (PRE_LATCH_TIME) 311. Assuming that the original preset latch time (PRE_LATCH_TIME) 311 is 10us, and the internal frequency maximum error value is +1us, then the maximum latch time (MAX_LATCH_TIME) 312 is 1us+10us=11us.

[0043] like Figure 7 , Figure 8 and Fig. 9As shown in the figure, the improved process of updating the LED brightness is that, first, when each chip 31 receives the corresponding CMD through DIN in a single-line transmission mode, it starts counting through the counter 311. Then, after each chip 31 counts the preset latch time (PRE_LATCH_TIME) 311, it will not immediately update the LED brightness. After the maximum latch time (MAX_LATCH_TIME) 312 has passed, the next step is that the synchronous signal receiver 312 receives the synchronous signal (SYNCSignal) through DIN, and immediately controls the switch 314 to conduct the line between the first data latch 313 and the second data latch 315, so that the CMD stored in the first data latch 313 is updated to the second data latch 315. Then, the second data latch 315 sends the CMD to the LED driver 316, and the LED driver 316 controls the output current according to the brightness adjustment parameter in the CMD, thereby updating the LED brightness.

[0044] Therefore, the maximum latch time (MAX_LATCH_TIME) 312 is further set in the chip 31. Even if the latch time (PRE_LATCH_TIME) 311 of each chip 31 is different, as long as it is confirmed that the synchronization signal (SYNC Signal) is received after the maximum latch time (MAX_LATCH_TIME) 312, all chips 31 can be set to the same time point T X The LED brightness is updated, and the LED brightness update time will no longer be affected by the internal frequency difference of each chip 31, so as to improve the display quality of the display device.

[0045] 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 single-line transmission synchronization circuit, characterized in that: include: A plurality of chips are connected in a single-line manner, a plurality of consecutive brightness control instructions are transmitted to the plurality of chips, the plurality of consecutive brightness control instructions are transmitted in a single-line manner between the plurality of chips, each chip takes out at least one corresponding brightness control instruction from the plurality of consecutive brightness control instructions and the remaining brightness control instructions are continuously transmitted to the next chip; Each chip includes an input terminal and an output terminal, and its circuit structure includes: A counter is connected to the input terminal and is set with a maximum latching time; Switches; A synchronous signal receiver connected to the input terminal, the counter and the switch; A first data latch is connected to the input end and the switch, receives the corresponding brightness control instruction from the input end and stores the corresponding brightness control instruction; A second data latch connected to the switch; and An LED driver connected to the second data latch and the output end; When each chip obtains the corresponding brightness control instruction, the counter starts counting; when the counter counts to the maximum value latch time, the synchronization signal receiver receives a synchronization signal and controls the switch to conduct the line between the first data latch and the second data latch, so as to update the corresponding brightness control instruction stored in the first data latch to the second data latch, and the LED driver obtains the corresponding brightness control instruction from the data latch and updates the brightness of the LED according to the corresponding brightness control instruction.

2. The single-wire transmission synchronization circuit according to claim 1, characterized in that: The counter is further set with a preset latching time, and the maximum latching time is the sum of the preset latching time and a maximum error value of the internal frequency of the chip.

3. The single-wire transmission synchronization circuit according to claim 1, characterized in that: The brightness control instruction includes a brightness adjustment parameter, and the LED driver controls the magnitude of the output current according to the brightness adjustment parameter of the brightness control instruction to update the brightness of the LED.

Images