CN113766697A - LED backlight system, driving chip thereof and processing method of main control chip - Google Patents
LED backlight system, driving chip thereof and processing method of main control chip Download PDFInfo
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Abstract
The invention provides an LED backlight system, a driving chip thereof and a processing method of a main control chip, wherein the processing method of the driving chip comprises the following steps: obtaining deviation information characterizing: the deviation degree and the deviation mode of the clock frequency between the driving chip and the main control chip connected with the driving chip indicate whether the deviation mode is larger or smaller; receiving dimming information sent by the main control chip; and compensating the dimming information based on the deviation information, and outputting a dimming signal based on the compensated dimming information. The scheme provided by the invention ensures the consistency of time response among the driving chips, and on the basis, a phase-locked loop PLL (phase-locked loop) does not need to be additionally arranged, so that the cost and the size of the chip are effectively reduced.
Description
Technical Field
The invention relates to the field of LEDs, in particular to an LED backlight system, a driving chip thereof and a processing method of a main control chip.
Background
In the field of LED backlight driving, in order to implement dynamic partition dimming, it is necessary to dynamically control the brightness of LED lamp beads in multiple channels. The LED backlight system can comprise LED driving chips and a main control chip, the number of LED channels which can be provided by a single LED driving chip is limited, a plurality of LED driving chips are often needed in one LED backlight plate, the main control chip controls the plurality of LED driving chips through a digital transmission interface, then the main control chip can send dimming information (which can also be understood as dimming parameters) to the LED driving chips, and the LED driving chips can send dimming signals to connected LED lamp beads based on the dimming information.
If the main control chip needs to broadcast the dimming information to a plurality of LED driving chips, then: the better the consistency of the time response of the dimming information of the LED driving chips is, the better the final dimming effect is. In the prior art, the consistency of time response is guaranteed, a SYNC pin needs to be added to an LED driving chip to transmit SYNC synchronous signals, and a phase-locked loop PLL needs to be contained in the LED driving chip. A plurality of LED driving chips needing synchronization share the same periodic SYNC signal, and a phase-locked loop PLL in each chip tracks the SYNC signal, so that the consistency of time reference among chips is achieved.
However, in this way, the size and cost of the chip will be increased by the introduction of the SYNC pin and the phase-locked loop PLL, and especially when the number of LED lamp beads is large, the increase in size and cost will be very obvious.
Disclosure of Invention
The invention provides an LED backlight system, a driving chip thereof and a processing method of a main control chip, which aim to solve the problems of increasing the size and cost of the chip.
According to a first aspect of the present invention, there is provided a processing method for a driving chip in an LED backlight system, including:
obtaining deviation information characterizing: the deviation degree and the deviation mode of the clock frequency between the driving chip and the main control chip connected with the driving chip indicate whether the deviation mode is larger or smaller;
receiving dimming information sent by the main control chip;
and compensating the dimming information based on the deviation information, and outputting a dimming signal based on the compensated dimming information.
Optionally, the obtaining deviation information includes:
acquiring reference counting information;
counting by using a counter of the driving chip in the process that the main control chip counts the reference counting information to obtain corresponding local counting information;
determining the deviation information based on the local count information and the reference count information.
Optionally, the deviation information is a ratio of the local counting information to the reference counting information, or information obtained based on the ratio.
Optionally, in the process that the main control chip counts the reference counting information, the counter of the driver chip is used for counting to obtain corresponding local counting information, where the process includes:
receiving a start command and a finish command sent by the main control chip, and controlling a counter of the drive chip to count based on the start command and the finish command to obtain the local counting information;
wherein a time interval between the close command and the start command matches: and the counter of the main control chip counts the duration of the reference counting information.
Optionally, the receiving a start command and a finish command sent by the main control chip, and controlling a counter of the driver chip to count based on the start command and the finish command to obtain the local counting information includes:
when a starting command sent by the main control chip is received, a counter of the driving chip is used for starting counting;
and when a finishing command sent by the main control chip is received, stopping counting of a counter of the driving chip to obtain the local counting information.
According to a second aspect of the present invention, there is provided a processing method for a main control chip in an LED backlight system, including:
determining reference counting information, and broadcasting the reference counting information to a driving chip connected with the main control chip;
broadcasting a starting command to the driving chip, and starting counting by using a counter of the main control chip;
broadcasting a finish command to the driving chip when the counter finishes counting the reference count information, such that: the driving chip can control a counter of the driving chip to count based on the start command and the finish command to obtain local counting information, and determine deviation information based on the local counting information and the reference counting information, wherein the deviation information represents a deviation degree and a deviation mode of clock frequency between the main control chip and the driving chip, and the deviation mode indicates a larger deviation or a smaller deviation;
sending dimming information to the driver chip such that: the driving chip can compensate the dimming information based on the deviation information and output a dimming signal based on the compensated dimming information.
Optionally, the deviation information is a ratio of the local counting information to the reference counting information, or information obtained based on the ratio.
According to a third aspect of the present invention, there is provided an LED backlight system comprising:
a driver chip for executing the processing method of the driver chip relating to the first aspect and its alternatives; and the main control chip.
According to a fourth aspect of the invention, a chip is provided for performing the steps of the method of the first or second aspect.
According to a fifth aspect of the present invention, there is provided a storage medium having code stored thereon, which when executed performs the steps of the method of the first or second aspect.
According to the LED backlight system, the driving chip and the processing method of the main control chip, after the driving chip obtains the deviation information, the dimming information can be compensated, the dimming signal is output based on the compensated dimming information, further, for the driving chip, the deviation of the clock frequency between the driving chip and the main control chip can be compensated based on the algorithm, the consistency of time response between the driving chips is guaranteed, on the basis, a phase-locked loop PLL (phase-locked loop) does not need to be additionally arranged, and the cost and the size of the chip are effectively reduced.
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In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.
FIG. 1 is a schematic diagram of an LED backlight system according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of an LED backlight system using a parallel topology according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of an LED backlight system using daisy chain topology according to an embodiment of the present invention;
FIG. 4 is a schematic diagram of dimming signals of three driver chips without the solution of the embodiment of the present invention;
FIG. 5 is a flowchart illustrating a processing method of a driver chip in an LED backlight system according to an embodiment of the invention;
FIG. 6 is a flowchart illustrating step S21 according to an embodiment of the present invention;
FIG. 7 is a flowchart illustrating step S212 according to an embodiment of the present invention;
FIG. 8 is a flowchart illustrating a processing method of a main control chip in the LED backlight system according to an embodiment of the present invention;
FIG. 9 is a schematic diagram of signal interaction of an LED backlight system according to an embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The terms "first," "second," "third," "fourth," and the like in the description and in the claims, as well as in the drawings, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
The technical solution of the present invention will be described in detail below with specific examples. The following several specific embodiments may be combined with each other, and details of the same or similar concepts or processes may not be repeated in some embodiments.
Referring to fig. 1 to fig. 3, an embodiment of the invention provides an LED backlight system, including: the LED driving circuit comprises a driving chip 102, a main control chip 101 and an LED unit 103. The driving chip 102 is respectively connected with the main control chip 101 and the LED unit 103.
The number of the driving chips 102, the main control chip 101, and the LED units 103 may be one or more, in a specific example, the number of the driving chips 102 connected to the same main control chip 101 is multiple, and further, the time response consistency of each driving chip 102 will affect the dimming effect, specifically, the better the time response consistency, the better the dimming effect. In addition, the driving chip of the present specification can also be described as an LED driving chip.
The LED unit 103 includes a plurality of LED beads, which can be controlled by the driving chip 102 after being connected in series and/or in parallel, and can emit light under the driving of the dimming signal of the driving chip 102.
In some examples, the LED unit 103 may further include a switch, the switch is connected to the plurality of LED beads, the driving chip may be connected to the switch, and the driving chip may drive the LED beads to emit light or not and adjust light by controlling on/off variation and/or on amplitude of the switch.
In some examples, the LED unit 103 may further include a current source connected to each LED bead in the LED unit 103, and the driving chip may also be connected to the current source, so as to control the current source to drive the LED beads to emit light or not and adjust the light.
The above is only an example, and the LED unit, regardless of the principle, circuit and structure, can be used as an alternative to the embodiment of the present invention as long as it can be driven by the driving chip to emit light.
The driving chip can output dimming signals under the control of the main control chip so as to drive the LED lamp beads of the LED units to emit light.
In the specific scheme, the dimming principle of the driving chip is divided into two types: DC dimming and PWM dimming. The former adjusts the brightness of the LED lamp bead by adjusting the magnitude of the channel constant current (namely, the current supplied to the LED lamp bead), and the latter adjusts the brightness by adjusting the opening and closing time duration of the LED channel (namely, the time duration of the high level output by the driving chip) in a periodic time period. The dimming signal according to the embodiment of the present invention may be a dimming signal in DC dimming or a dimming signal in PWM dimming.
Corresponding to the two dimming principles, for DC dimming, the dimming information sent by the main control chip to the driving chip may be information representing the magnitude of the corresponding current; for PWM dimming, the dimming information sent by the main control chip to the driving chip may be information representing a duration corresponding to a high level.
Further, the dimming information and the dimming signal according to any of the dimming principles can be used as a configuration of the embodiment of the present invention.
The LED backlight system of the embodiment of the invention may adopt a parallel topology (for example, as shown in fig. 2) or a daisy chain topology (for example, as shown in fig. 3).
The driver chip in the embodiment of the present invention may be understood as a processing method for executing the driver chip according to the present specification. The main control chip in the embodiment of the present invention may be understood as a processing method for executing the main control chip related to this specification.
In addition, the following specific examples (for example, the following specific examples of the methods) are mainly described with respect to the scheme of PWM dimming, and the embodiments of the present invention do not exclude the possibility of implementing the methods under DC dimming.
In order to clearly show the advantages of the embodiments of the present invention, the following will specifically describe the reason and practical results of the poor consistency of the time response by combining the waveforms shown in fig. 4 and the LED backlight system with the structure shown in fig. 2:
an oscillator circuit inside the LED driving chip generates a basic clock required for the digital circuit to operate, assuming that the designed frequency of the clock is 10 MHz. Due to manufacturing variations, the frequency of this clock is not exactly 10MHz consistent even for the same batch of chips. For example, assuming a certain batch of 10000 LED driver chips, the clock frequency may be in a range of 9.5MHz + -20%. This clock skew can lead to degraded dimming performance if the inter-chip time reference consistency is not handled.
In the case of the LED backlight system adopting the structure shown in fig. 2, the internal oscillator frequencies of the three driver chips A, B, C are assumed to be 10.5MHz, 9MHz, and 11MHz, respectively. The main control chip will send a common PWM dimming parameter (i.e. dimming information) to all channels, for example, set the PWM period to 0x8000 (representing the duration of 0x8000 internal counting periods), the high level of PMW to 0x4000, and the rising edge offset of PWM to 0. The PWM waveforms actually output by the three driver chips are roughly as shown in fig. 4.
Due to the difference of the reference frequency, the PWM waveforms output by different driving chips are not consistent, and the accumulated deviation is increased continuously.
Referring to fig. 5, an embodiment of the present invention provides a method for processing a driving chip in an LED backlight system, including:
s21: acquiring deviation information;
s22: receiving dimming information sent by the main control chip;
s23: and compensating the dimming information based on the deviation information, and outputting a dimming signal based on the compensated dimming information.
The deviation information characterizes: the deviation degree and the deviation mode of the clock frequency between the driving chip and the main control chip connected with the driving chip indicate whether the deviation mode is larger or smaller; the deviation degree can be expressed as the deviation amount itself or as the ratio of the deviation amount to the clock frequency of the chip. Moreover, no matter what manner is adopted to enable the driver chip to acquire the deviation information, the scope of the embodiment of the present invention is not deviated, and meanwhile, in the acquiring process, the storage of the deviation information may also be implemented for the retrieval of the deviation information in the subsequent step S23.
The dimming information and the dimming signal can be understood by referring to the description in the foregoing of the present specification, for example: the dimming information may be indicative of a duration of the high level in a single period of the dimming signal output by the driving chip (or a ratio of the duration of the high level in the single period).
Compensation therein is to be understood as:
if the clock frequency of the driving chip is larger than that of the main control chip, then: in PWM dimming, the duration of the high level in a single period can be increased through the compensation, and in other examples, in DC dimming, the compensation can also be, for example, to increase the current; correspondingly, the specific amount of compensation may be adapted to change based on the degree of deviation characterized by the deviation information;
if the clock frequency of the driving chip is smaller than that of the main control chip, then: in PWM dimming, the duration of the high level in a single period can be reduced by the compensation, and in other examples, in DC dimming, the compensation can also be, for example, to reduce the current; accordingly, the particular amount of compensation can be adapted to change based on the degree of deviation characterized by the deviation information.
Therefore, in the above scheme, each driver chip calculates and stores the deviation degree of the self clock from the time and frequency reference of the main control chip. When each driving chip subsequently receives the dimming parameters (namely dimming information) related to the time base, reverse compensation is carried out according to the deviation information stored by the driving chip, and therefore consistency of time references among chips is achieved.
In one embodiment, referring to fig. 6, step S21 may include:
s211: acquiring reference counting information;
s212: counting by using a counter of the driving chip in the process that the main control chip counts the reference counting information to obtain corresponding local counting information;
s213: determining the deviation information based on the local count information and the reference count information.
The reference counting information may be understood as counting information serving as a reference, and correspondingly, for the main control chip, a time duration corresponding to the reference counting information may be understood as a reference time duration, which may be specifically understood as: the time length of the counter of the main control chip for completing the counting process of the reference counting information is the reference time length.
In one example, the reference count information may be, for example, 0xF000, and the corresponding reference duration may be, for example, 6.144 ms. The reference time length and the reference technical information are only examples, and do not depart from the scope of the embodiments of the present invention.
In a specific example, step S212 may include:
receiving a start command and a finish command sent by the main control chip, and controlling a counter of the drive chip to count based on the start command and the finish command to obtain the local counting information;
wherein a time interval between the close command and the start command matches: and the counter of the main control chip counts the duration of the reference counting information.
Furthermore, in the above example, the driving chip may count (i.e. time) under the control and indication of the main control chip, so as to accurately embody the actual counting result (i.e. local counting information) of the driving chip in the process of the main control chip timing reference duration, and further, the deviation information may be calibrated by using the local counting information and the reference counting information.
In some examples, the step S212 may be repeated multiple times, and further, for one driver chip, multiple pieces of local count information may be obtained, and further, the deviation information may be calculated based on a statistical value (e.g., an average value) of the multiple pieces of local count information and the reference count information.
In a corresponding example, the deviation information is a ratio of the local count information to the reference count information, or information obtained based on the ratio (e.g., information obtained by adjusting a ratio based on experience or other circuit principles).
In addition, in a partial scheme different from the process shown in fig. 6, the driver chip may not perform steps S211 and S213, and further, in the case of performing step S212, the local count information is sent to the main control module, and then the main control module is used to determine the deviation information; in another embodiment, a reference count information may be determined by the driver chips (at this time, each driver chip needs to determine a reference count information), and then the process similar to steps S211 to S213 is implemented by using the main control module. Meanwhile, the process shown in fig. 6 is a preferred embodiment from the viewpoint of computational efficiency and accuracy. It is also understood that the process of step S21 shown in fig. 5 may not be limited to the embodiment shown in fig. 6, and may cover a wider range.
In an example, referring to fig. 7, the step S212 may specifically include:
s2121: when a starting command sent by the main control chip is received, a counter of the driving chip is used for starting counting;
s2122: and when a finishing command sent by the main control chip is received, stopping counting of a counter of the driving chip to obtain the local counting information.
In other examples different from fig. 7, counting may be started after delaying after receiving the start command, and/or stopped after delaying after receiving the end command; for example, to compensate for delays in signal transmission.
Referring to fig. 8 for the processing procedure of the above driving chip, an embodiment of the present invention further provides a processing method of a main control chip, including:
s31: determining reference counting information, and broadcasting the reference counting information to a driving chip connected with the main control chip;
s32: broadcasting a starting command to the driving chip, and starting counting by using a counter of the main control chip;
s33: broadcasting a finish command to the driving chip when the counter finishes counting the reference counting information;
further, by step S33, it is possible to make: the driving chip can control a counter of the driving chip to count based on the start command and the finish command to obtain local counting information, and determine deviation information based on the local counting information and the reference counting information, wherein the deviation information represents a deviation degree and a deviation mode of clock frequency between the main control chip and the driving chip, and the deviation mode indicates a larger deviation or a smaller deviation;
s34: sending dimming information to the driving chip;
further, by step S34, it is possible to make: the driving chip can compensate the dimming information based on the deviation information and output a dimming signal based on the compensated dimming information.
Technical terms, technical effects and alternatives in the above steps can be understood by referring to the related description in the foregoing, and are not repeated herein.
A specific solution of the embodiment of the present invention will be described below with reference to fig. 8 and 9:
the main control chip 101 may determine the reference count information first, for example, the main control chip 101 may determine that the reference clock frequency of the transmitted dimming parameter (i.e., the dimming information) is 10 MHz; correspondingly, the calibration reference counter of the main control chip 101 takes a value of 0xF000 (that is, the reference count information takes 0xF000), and the corresponding reference time duration may be 6.144 ms;
after determining the reference technology information, the main control chip 101 may broadcast the reference count information to each of the driver chips 102 connected thereto, for example, the main control chip 101 may broadcast a notification to all the driver chips 102 to learn that the calibration reference counter takes a value of 0xF 000;
correspondingly, after receiving the broadcast notification from the main control chip 101, the driver chip 102 may obtain reference count information, for example, set the value of the reference calibration counter to 0xF 000;
then, the main control chip 101 may start counting (i.e., start timing of the reference time duration) by using the counter of the main control chip, and at the same time, may broadcast a start command to the driver chip 102 to which it is connected, and precisely wait for the reference time duration (e.g., 6.144ms), and the main control chip 101 may broadcast a finish command to the driver chip 102 to which it is connected after completing counting of the reference counting information (i.e., timing waiting of the reference time duration of, for example, 6.144 ms);
correspondingly, the driver chip 102 may start counting by using the counter of the driver chip when receiving the start command, and stop counting by using the counter of the driver chip when receiving the end command, so as to obtain local counting information, for example: when a start command is received, starting a local calibration counter to count according to an internal clock of the driving chip, and when a finish command is received, stopping counting of the local calibration counter, wherein at the moment, the value of the local calibration counter can be obtained and used as local counting information;
after obtaining the local count information, the driver chip 102 may calculate a ratio R between the local calibration counter value (i.e., the local count information) and the reference calibration counter value (i.e., the reference count information), which may be further used as the deviation information, that is: determining the deviation information based on the local count information and the reference count information.
By the above procedure, the determination of deviation information (also understood as calibration) is then achieved.
In the subsequent control process, the main control chip 101 may send dimming information to the driving chip 102, and the driving chip may compensate the dimming information based on the deviation information and output a dimming signal based on the compensated dimming information. For example: after the driving chip 102 receives the dimming parameter (i.e., dimming information), the dimming information may be, for example, PWM high level 0x4000, and when the dimming information is compensated based on this, local actual PWM high level 0x4000 xr may be calculated as compensated dimming information; then, the PWM waveform may be output based on the compensated dimming information.
The specific quantitative calculation process may be, for example:
for example, trial calculation. Referring to fig. 4, the frequency of the a-driver chip is 10.5MHz, the frequency of the reference clock is 10MHz, and the calibration reference counter is 0xF000 (i.e., the reference count information is 00xF000), at this time, the value of the a-driver chip local calibration counter should be 0xFC00 (i.e., the local count information is 0xFC00), the deviation information R is 0xFC00/0xF000 is 1.05, if the nominal PMW high level is 0x4000 (i.e., the dimming information is characterized as 0x4000), then: the local PMW high level parameter calculation of the a driver chip may obtain 0x4000 × 1.05 ═ 0x4333 (i.e., the adjusted dimming information is characterized as 0x 4333).
It can be seen that when the local clock frequency is higher than the reference clock frequency, the dimming parameter compensated by calibration becomes larger accordingly. The shortened clock period and the increased clock period cancel each other out, so that a uniform output waveform is obtained. The case where the local clock frequency is lower than the reference clock frequency is analogized in turn.
Besides the above description, the digital transmission interface protocol between the master chip and the slave driver chip may be the SPI protocol, and may not be limited to the SPI protocol.
The embodiment of the invention also provides a chip which is used as a main control chip or a drive chip and further can execute a processing method of the main control chip or a processing method of the drive chip.
Embodiments of the present invention also provide a computer-readable storage medium on which a computer program is stored, which when executed (e.g., by a processor or processing module) implements the above-mentioned method.
In summary, in the embodiments of the present invention, after the driving chip obtains the deviation information, the dimming information may be compensated, and the dimming signal is output based on the compensated dimming information, and further, for the driving chip, the deviation of the clock frequency between the driving chip and the main control chip may be compensated based on the algorithm, so as to ensure the consistency of the time response between the driving chips.
Those of ordinary skill in the art will understand that: all or a portion of the steps of implementing the above-described method embodiments may be performed by hardware associated with program instructions. The program may be stored in a computer-readable storage medium. When executed, the program performs steps comprising the method embodiments described above; and the aforementioned storage medium includes: various media that can store program codes, such as ROM, RAM, magnetic or optical disks.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.
Claims (10)
1. A processing method for a driving chip in an LED backlight system is characterized by comprising the following steps:
obtaining deviation information characterizing: the deviation degree and the deviation mode of the clock frequency between the driving chip and the main control chip connected with the driving chip indicate whether the deviation mode is larger or smaller;
receiving dimming information sent by the main control chip;
and compensating the dimming information based on the deviation information, and outputting a dimming signal based on the compensated dimming information.
2. The processing method of the driver chip according to claim 1,
the acquiring deviation information includes:
acquiring reference counting information;
counting by using a counter of the driving chip in the process that the main control chip counts the reference counting information to obtain corresponding local counting information;
determining the deviation information based on the local count information and the reference count information.
3. The processing method of the driver chip according to claim 2, wherein the deviation information is a ratio of the local count information to the reference count information, or information obtained based on the ratio.
4. The processing method of the driver chip according to claim 2,
in the process that the main control chip counts the reference counting information, the counter of the driving chip is used for counting to obtain corresponding local counting information, and the method comprises the following steps:
receiving a start command and a finish command sent by the main control chip, and controlling a counter of the drive chip to count based on the start command and the finish command to obtain the local counting information;
wherein a time interval between the close command and the start command matches: and the counter of the main control chip counts the duration of the reference counting information.
5. The processing method of the driver chip according to claim 4,
receiving a start command and a finish command sent by the main control chip, and controlling a counter of the driving chip to count based on the start command and the finish command to obtain the local counting information, including:
when a starting command sent by the main control chip is received, a counter of the driving chip is used for starting counting;
and when a finishing command sent by the main control chip is received, stopping counting of a counter of the driving chip to obtain the local counting information.
6. A processing method of a main control chip in an LED backlight system is characterized by comprising the following steps:
determining reference counting information, and broadcasting the reference counting information to a driving chip connected with the main control chip;
broadcasting a starting command to the driving chip, and starting counting by using a counter of the main control chip;
broadcasting a finish command to the driving chip when the counter finishes counting the reference count information, such that: the driving chip can control a counter of the driving chip to count based on the start command and the finish command to obtain local counting information, and determine deviation information based on the local counting information and the reference counting information, wherein the deviation information represents a deviation degree and a deviation mode of clock frequency between the main control chip and the driving chip, and the deviation mode indicates a larger deviation or a smaller deviation;
sending dimming information to the driver chip such that: the driving chip can compensate the dimming information based on the deviation information and output a dimming signal based on the compensated dimming information.
7. The processing method of the main control chip according to claim 6, wherein the deviation information is a ratio of the local count information to the reference count information, or information obtained based on the ratio.
8. An LED backlight system, comprising:
a driver chip for performing the processing method of the driver chip of any one of claims 1 to 5; and the main control chip.
9. A chip for performing the steps of the method of any one of claims 1 to 8.
10. A storage medium having code stored thereon, wherein the code when executed performs the steps of the method of any of claims 1-8.
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