Data transmission interruption control method for serial communication in LED backlight driving

Abstract

The invention discloses a data transmission interruption control method for serial communication in an LED (light-emitting diode) backlight driver, and the LED backlight driver comprises a serial communication link consisting of an upper computer and a plurality of driving chips. The control method comprises the following steps: data signals sent to a driving chip by an upper computer comprise a first signal, a second signal and a third signal; wherein the first signal is an idle signal, and the idle signal indicates that the upper computer does not send driving data to the driving chip; the second signal represents a driving data signal sent to the driving chip by the upper computer, and the second signal comprises at least two data segments; the third signal is located between the data segments of the two second signals and represents the interruption state of the data transmission.

Description

Technical Field

[0001] The present invention relates to the technical field of LED backlight driving, and particularly to a method for controlling data transmission interruption in serial communication in LED backlight driving. Background Art

[0002] In the field of backlight display, generally, BCON (backlighting control) is used to send backlight information to the backlight driving chip to control the brightness of Mini-LEDs. Some manufacturers also adopt the BCONLESS solution, mainly to reduce the complexity and cost of the system. Generally, an SoC control chip is used to replace the BCON chip. The types of SoCs used by each manufacturer are diverse, resulting in different capabilities of receiving and sending backlight information. Due to the increasing number of Mini-LED driving chips now, the brightness information to be sent to the driving chips is also increasing, resulting in some Socs being unable to continuously send the brightness information. Therefore, we propose a control method for serial data of the slave (LED driving chip) when the data sent by the Master (Soc chip) is interrupted in the context of BCONLESS, which can ensure the integrity and correctness of the brightness information.

[0003] The LED brightness information is sent by the host computer (implemented by Soc or other control components) with the brightness data of a whole frame. Since Soc or other control components do not have enough resources to support sending the whole frame of data, the existing technical solution is that Soc works both in receiving and sending simultaneously, reducing the resources occupied by Soc, and using the limited storage capacity and data processing ability to support the sending of brightness. Generally speaking, the brightness data of a whole frame can be decomposed into several data frames and sent to the LED driving chip sequentially. The disadvantages of this solution are: the time for Soc to send backlight data will increase, the data bandwidth will be occupied (the frame header and frame tail need to be resent each time), and at the same time, it will also affect the effective time of the brightness data.

[0004] It can be seen that there is a need for a new method for controlling data transmission interruption in serial communication in LED backlight driving in the prior art. Summary of the Invention

[0005] The technical objective to be achieved by the present invention is to provide a method for controlling data transmission interruption in serial communication in LED backlight driving. For some Socs, data can be continuously sent without being decomposed into several frames; if the data received by Soc has not been processed well, the frame data can be temporarily put into a "holding" state until a new brightness is received, and then the next bit of data is sent continuously.

[0006] Based on the above technical objectives, the present invention provides a method for controlling data transmission interruption in serial communication in LED backlight driving. The LED backlight driving includes a serial communication link composed of a host computer and multiple driving chips. The control method includes:

[0007] The data signals sent from the host computer to the driving chips include: a first signal, a second signal, and a third signal;

[0008] Wherein the first signal is an idle signal, and the idle signal indicates that the host computer does not send driving data to the driving chip;

[0009] The second signal represents a driving data signal sent from the host computer to the driving chip, and the second signal includes at least two data segments;

[0010] The third signal is located between the data segments of two second signals, and it represents the interruption state of data transmission;

[0011] Further, the first data segment of the second signal is located after the first signal, and the duration between the first signal rising edge and the adjacent next signal rising edge, or the duration between the first signal falling edge and the adjacent next signal falling edge of the first data segment is defined as a signal bit duration T;

[0012] And the first signal is a constant first-level state signal, the third signal is a constant second-level state, and the duration of the first signal and the duration of the third signal both exceed a signal bit duration T.

[0013] In one embodiment, when the duration of the first-level state in each signal bit of the second signal exceeds T / 2, this signal bit represents the binary value 1, and when the duration of the second-level state exceeds T / 2, this signal bit represents the binary value 0.

[0014] In one embodiment, when the host computer switches from the idle state to sending driving data to the driving chip, the host computer first pulls the first signal from the first-level state to the second-level state.

[0015] In one embodiment, when the host computer needs to enter the interruption sending state after sending a data segment of the second signal, the host computer directly sends the third signal.

[0016] In one embodiment, when the host computer switches from the interruption sending state to the data sending state to send a data segment of the second signal, the host computer directly sends the data segment of the second signal to be sent.

[0017] The present invention provides a method for controlling data transmission interruption in serial communication in LED backlight driving. The LED backlight driving includes a serial communication link composed of a host computer and multiple driving chips. The control method includes:

[0018] The data signals sent from the host computer to the driving chips include: a first signal, a second signal, and a third signal;

[0019] Wherein the first signal is an idle signal, and the idle signal indicates that the host computer does not send driving data to the driving chip;

[0020] The second signal represents the driving data signal sent from the host computer to the driving chip, and the second signal includes at least two data segments;

[0021] The third signal is located between the data segments of two second signals, and it represents the interruption state of data transmission;

[0022] Further, the first data segment of the second signal is located after the first signal, and the duration between the first signal rising edge of the first data segment and the adjacent next signal rising edge, or the duration between the first signal falling edge and the adjacent next signal falling edge is defined as a signal bit duration T;

[0023] And the first signal is a constant first-level state signal, the third signal includes a first-level state maintenance segment and a second-level maintenance segment, and the duration of the first signal and the duration of the second-level maintenance segment of the third signal both exceed a signal bit duration T.

[0024] In one embodiment, when the duration of the first-level state in each signal bit of the second signal exceeds T / 2, the signal bit represents the binary value 1, and when the duration of the second-level state exceeds T / 2, the signal bit represents the binary value 0.

[0025] In one embodiment, when the host computer changes from the idle state to sending driving data to the driving chip, the host computer directly sends the data segment of the second signal to be sent.

[0026] In one embodiment, when the host computer needs to enter the interruption sending state after sending a data segment of the second signal, the host computer directly sends the second-level maintenance segment of the third signal.

[0027] In one embodiment, when the host computer changes from the interruption sending state to the data sending state to send a data segment of the second signal, the host computer first pulls the third signal from the second-level maintenance segment to the first-level state maintenance segment.

[0028] Other features and advantages of the present invention will be set forth in the following description, and in part will be obvious from the description, or may be learned by practice of the present invention. The objectives and other advantages of the present invention may be realized and attained by the structure particularly pointed out in the specification, claims as well as the drawings. Description of the Drawings

[0029] The drawings are used to provide a further understanding of the present invention, and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention, and do not constitute a limitation to the present invention. In the drawings:

[0030] Figure 1 is a schematic structural diagram of the LED backlight driving system of the present invention;

[0031] Figure 2 is a schematic diagram of the data format of the first embodiment of the present invention;

[0032] Figure 3 is a schematic diagram of the data format of the second embodiment of the present invention. Detailed Embodiments

[0033] To make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the drawings.

[0034] It should be understood that when an element or layer is referred to as being "on", "adjacent to", "connected to" or "coupled to" another element or layer, it can be directly on, adjacent to, connected or coupled to the other element or layer, or there may be intervening elements or layers. In contrast, when an element is referred to as being "directly on", "directly adjacent to", "directly connected to" or "directly coupled to" another element or layer, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Thus, without departing from the teachings of the present invention, the first element, component, region, layer or part discussed below may be denoted as the second element, component, region, layer or part. And when discussing the second element, component, region, layer or part, it does not imply that the present invention necessarily has a first element, component, region, layer or part.

[0035] Spatial relationship terms such as "under", "below", "lower", "beneath", "above", "upper", etc. may be used herein for convenience of description to describe the relationship of one element or feature shown in the figures with other elements or features. It should be understood that, in addition to the orientations shown in the figures, spatial relationship terms are also intended to include different orientations of the device in use and operation. For example, if the device in the drawings is flipped, then an element or feature described as "under other elements" or "beneath them" or "under them" will be oriented "above" the other elements or features. Thus, the exemplary terms "under" and "beneath" can include both the upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or other orientations) and the spatial descriptors used herein are to be interpreted accordingly.

[0036] The purpose of the terms used herein is only to describe specific embodiments and is not a limitation of the present invention. As used herein, the singular forms "a", "an" and "the" are also intended to include the plural forms unless the context clearly dictates otherwise. It should also be understood that the terms "comprising" and / or "including", when used in this specification, identify the presence of the stated features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups. As used herein, the term "and / or" includes any and all combinations of the associated listed items.

[0037] Example 1

[0038] As Figure 1 shown in the LED driving system of the present invention, the LED driving system includes: a host SOC and a plurality of LED driving chips Chip1 to Chip4; the host SOC and the plurality of LED driving chips Chip1 to Chip4 form a serial communication link, and the host SOC sends instruction data to the plurality of LED driving chips Chip1 to Chip4 as slaves.

[0039] Each of the LED driving chips has a plurality of LED driving channel pins LED1 to LED4, and the LED driving channel pins are used to connect an LED string to directly control the light emission of the LED string.

[0040] Each of the LED driving chips is provided with a data input port Din and a data output port Dout. The serial communication link means that the data input port Din of each LED driving chip is connected to the data output port Dout of the previous-level LED driving chip adjacent to this LED driving chip, and the data output port Dout of each LED driving chip is connected to the data input port Din of the next-level LED driving chip adjacent to this LED driving chip. The data input port Din of the first LED driving chip in the serial communication link is connected to the signal output port of the host computer SOC.

[0041] The output port of the last LED driving chip is connected to the data input port of the host computer SOC, or the data is sent back to the host computer SOC in reverse through a single data line by the last LED driving chip.

[0042] As Figure 2 shown, the data signals sent by the host computer SOC of the present invention to the driving chip include: a first signal, a second signal, and a third signal. Among them, the first signal is an "idle" signal, and the "idle" signal indicates that the host computer SOC does not send driving data to the driving chip. The second signal represents the driving data sent by the host computer SOC to the driving chip, and the second signal includes at least two data segments. The third signal is located between the data segments of two second signals, and it represents the "interruption" of data transmission.

[0043] In this embodiment, the first signal is in a constant first level state (high level); the second signal is a signal in which the first level state and the second level state (low level) alternate. The first rising edge after the first signal is used as the starting point of the second signal, and the duration between the first rising edge and the second rising edge is defined as the duration T of one signal bit of the driving data. When the duration of the first level state in each signal bit of the second signal exceeds T / 2, this signal bit represents the binary value "1", and when the duration of the second level state exceeds T / 2, this signal bit represents the binary value "0". The third signal is in a constant second level state.

[0044] In this embodiment, the third signal is located between different segments of the second signal. Since the second signal starts with a rising edge, in the first part of each signal bit duration of the second signal, it is in the first level state, and the second part is in the second level state. Therefore, when the transmission of the previous segment of the second signal ends and the driving data transmission enters the "interrupt" state, the third signal remains in the second level state, which is equivalent to extending the duration of the second level in the last signal bit of the previous segment of data. Since the duration of the first level in the last signal bit of the previous segment of data has been determined, the extension of the second level state will not affect the reading of 1 or 0 of this signal bit. At the same time, only when the third signal ends, that is, when the rising edge of the first signal bit of the next segment of the second signal arrives, the driving chip continues to receive the driving data.

[0045] In this embodiment, the durations of the first signal and the third signal are both set to be longer than the duration T of one signal bit of the second signal, so as to clearly distinguish them from the driving data in the second signal.

[0046] Example 2

[0047] As Figure 3 shown, the data signal sent by the host computer SOC of the present invention to the driving chip includes: a first signal, a second signal, and a third signal. The first signal is an "idle" signal, and the "idle" signal indicates that the host computer SOC does not send driving data to the driving chip. The second signal represents the driving data sent by the host computer SOC to the driving chip, and the second signal includes at least two data segments. The third signal is located between the data segments of the two second signals, and it represents the "interrupt" of data transmission.

[0048] In this embodiment, the first signal is in a constant second level state (low level); the second signal is a signal with alternating first level state and second level state (low level). The first rising edge after the first signal is used as the starting point of the second signal, and the duration between the first rising edge and the second rising edge is defined as the duration T of one signal bit of the driving data. When the duration of the first level state in each signal bit of the second signal exceeds T / 2 and is less than T, this signal bit represents the binary value "1", and when the duration of the second level state exceeds T / 2 and is less than T, this signal bit represents the binary value "0". The third signal includes a first level state maintaining segment and a second level maintaining segment, and the first level state maintaining segment exceeds the duration T of one signal bit of the second signal. Thus, the driving chip can recognize the third signal and clearly know that the data transmission enters the "interrupt" state.

[0049] In this embodiment, the third signal is located between different segments of the second signal. Since the second signal uses the rising edge as the signal start, in the first part within the signal bit duration of each second signal, it is in the first level state, and the latter part is in the second level state. Therefore, when the current segment of the second signal transmission ends and the drive data transmission enters the "interrupt" state, if the third signal maintains the first level state for more than one signal bit duration T, the drive chip can determine that this signal is the transmission "interrupt" signal. When the host SOC needs to perform the transmission of the next segment of the second signal, it will first pull down the third signal and start transmitting the next segment of the second signal at the next rising edge. That is, when the rising edge of the first signal bit of the next segment of the second signal arrives, the drive chip continues to receive the drive data.

[0050] In this embodiment, the durations of the first signal and the third signal are both set to be longer than one signal bit duration T in the second signal to clearly distinguish them from the drive data in the second signal.

[0051] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present application.

Claims

1. A data transmission interruption control method for serial communication in LED backlight driving, wherein the LED backlight driving includes a host computer and a serial communication link composed of multiple driving chips, and is characterized in that, The control method includes: The data signals sent from the host computer to the driving chip include: a first signal, a second signal, and a third signal; Wherein the first signal is an idle signal, and the idle signal indicates that the host computer does not send driving data to the driving chip; The second signal represents the driving data signal sent from the host computer to the driving chip, and the second signal includes at least two data segments; The third signal is located between the data segments of two second signals, and it represents the interruption state of data transmission; Further, the first data segment of the second signal is located after the first signal, and the duration between the first signal rising edge and the adjacent next signal rising edge of the first data segment, or the duration between the first signal falling edge and the adjacent next signal falling edge is defined as a signal bit duration T; And the first signal is a constant first-level state signal, the third signal is a constant second-level state, and at the same time, the duration of the first signal and the duration of the second-level maintenance segment of the third signal both exceed a signal bit duration T.

2. The data transmission interruption control method according to claim 1, wherein When the duration of the first-level state in each signal bit of the second signal exceeds T / 2, this signal bit represents the binary value 1, and when the duration of the second-level state exceeds T / 2, this signal bit represents the binary value 0.

3. The data transmission interruption control method according to claim 1, characterized in that When the host computer changes from the idle state to sending driving data to the driving chip, the host computer first pulls the first signal from the first-level state to the second-level state.

4. The data transmission interruption control method according to claim 1, wherein When the host computer needs to enter the interruption sending state after sending a data segment of the second signal, the host computer directly sends the third signal.

5. The data transmission interruption control method according to claim 1, wherein When the host computer changes from the interruption sending state to the data sending state to send a data segment of the second signal, the host computer directly sends the data segment of the second signal to be sent.

6. A method for controlling data transmission interruption in serial communication in LED backlight driving, wherein the LED backlight driving includes a host computer and a serial communication link composed of multiple driving chips, and is characterized in that, The control method includes: The data signals sent from the host computer to the driving chip include: a first signal, a second signal, and a third signal; Wherein the first signal is an idle signal, and the idle signal indicates that the host computer does not send driving data to the driving chip; The second signal represents the driving data signal sent from the host computer to the driving chip, and the second signal includes at least two data segments; The third signal is located between the data segments of two second signals, and it represents the interruption state of data transmission; Further, the first data segment of the second signal is located after the first signal, and the duration between the first signal rising edge and the adjacent next signal rising edge of the first data segment, or the duration between the first signal falling edge and the adjacent next signal falling edge is defined as a signal bit duration T; And the first signal is a constant first-level state signal, the third signal includes a first-level state maintenance segment and a second-level maintenance segment, and at the same time, the duration of the first signal and the duration of the second-level maintenance segment of the third signal both exceed a signal bit duration T.

7. The data transmission interruption control method according to claim 6, wherein When the duration of the first level state in each signal bit of the second signal exceeds T / 2, the signal bit represents the binary value 1. When the duration of the second level state exceeds T / 2, the signal bit represents the binary value 0.

8. The data transmission interruption control method according to claim 6, wherein When the host computer converts from the idle state to sending drive data to the drive chip, the host computer directly sends the data segment of the second signal to be sent.

9. The data transmission interruption control method according to claim 1, wherein When the host computer needs to enter the interrupt sending state after sending a data segment of the second signal, the host computer directly sends the second level maintenance segment of the third signal.

10. The data transmission interruption control method according to claim 1, wherein When the host computer converts from the interrupt sending state to the data sending state to send a data segment of the second signal, the host computer first pulls the third signal from the second level maintenance segment to the first level state maintenance segment.

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