Gamma correction circuit, method, device and medium for OLED driver chip based on MRAM

Abstract

The present invention relates to an MRAM-based OLED driver chip Gamma correction circuit and method, equipment, and medium, and relates to the technical field of chip devices and circuit design. The circuit includes an MRAM storage logic control circuit, a grayscale detection circuit, a resistor selection circuit, a differential amplifier circuit, a grayscale voltage divider circuit, and an OLED pixel driving circuit. The Gamma correction circuit in the OLED driver chip of the present invention uses MRAM as a storage unit, which not only has the ability to store data when the power is off, but also has low energy consumption and high speed for reading and writing, and greatly improves the reliability of data storage. Compared with the traditional OTP memory, the present invention uses MRAM as a storage unit and has the ability to be repeatedly erased and written. Therefore, the correction circuit can fine-tune the Gamma numerical parameters multiple times, more accurately control the OLED voltage, improve the display effect and extend the service life. The present invention can reduce the chance of OLED Gamma calibration errors, and the OLED has the opportunity to be retested and corrected at any time, reducing the cost of error risks.

Description

Technical Field

[0001] The present invention relates to the technical field of chip devices and circuit design, and in particular to a Gamma correction circuit and method, device and medium for an OLED driver chip based on MRAM. Background Art

[0002] Organic Light-Emitting Diode (OLED), also known as organic electric laser display and organic light-emitting semiconductor, refers to a device that emits light through carrier injection and recombination when organic semiconductor materials and luminescent materials are driven by an electric field. Compared with LCD, OLED has the characteristics of ultra-thin, self-luminous, wide viewing angle, fast response, high luminous efficiency, good temperature adaptability, low driving voltage, and low energy consumption. The use of OLED has become a development trend in the future display industry. OLED has a very broad application prospect and can provide new display methods for terminal product manufacturers such as home appliances, communications, computers, instruments and meters, and also bring consumers a cheaper portable, browsing, reading and viewing experience.

[0003] LED production requires multiple processes, one of which is grayscale gamma adjustment. OLED grayscale gamma adjustment mainly adjusts the brightness value of the OLED gray display screen, making the display screen more adaptable to the human eye's response to changes in brightness and achieving a better display effect. Gamma adjustment is to change the input voltage value by adjusting the register in the OLED drive circuit, thereby changing the output of the OLED brightness. On the one hand, it can achieve a display effect of uniform brightness change perceived by the human eye, and on the other hand, it can also partially repair defects such as water ripples, thereby improving and improving product yield.

[0004] Gamma correction power management chips are mainly based on analog circuits. Affected by errors such as process manufacturing, chips that are taped out often need parameter calibration. By adding OTP and registers to the chip, the determined value is burned into the OTP after debugging. After the chip is powered on, the OTP value is loaded into the register, and the analog circuit parameters are calibrated. Figure 1It is a common Gamma chip circuit system block diagram. After the chip is powered on, the OTP value is loaded into the register to complete the parameter calibration of the analog circuit. The embedded low-speed interface IP (usually I2C / SPI / UART, etc.) facilitates the reading and writing of OTP and registers, which greatly improves the convenience of debugging. Among them, the core device of the register generally adopts OTP (one time programmable) device, that is, one-time programmable device, which belongs to non-volatile memory. The main purpose of using OTP is to store the gamma calibration voltage value when the power of the OLED screen is turned off, and the stored voltage value can be directly called for screen grayscale adjustment at the next startup. Therefore, the OTP circuit module needs to have the ability to support programming and the characteristics of non-volatility when power is off.

[0005] The memory required by the gamma correction circuit needs to meet the following conditions: 1. It has power-off non-volatility, ensuring that the voltage value required for pixel calibration can still be stored when the OLED is powered off; 2. Fast reading and writing speed, so that when the OLED works again, the voltage value in the memory can be quickly called up to quickly calibrate the OLED pixels; 3. Stability of multiple readings and reliability of data retention to extend the service life of the OLED. The current gamma correction circuit uses OTP devices, whether it is a fuse type or an anti-fuse type, which has certain defects in reading speed, reliability and energy consumption.

[0006] MRAM (Magnetic Random Access Memory) refers to a random access memory that stores data using magnetoresistance properties. It uses different magnetoresistance caused by different magnetization directions to record 0 and 1. As long as the external magnetic field does not change, the magnetization direction will not change. Therefore, it has non-volatile storage performance. As the next generation of new MRAM memory, MRAM has fast read and write speeds (less than 10ns), nearly unlimited read times (read times greater than 10e16), supports multiple erases (erases and writes greater than 10e13), and has a reliability of more than 10 years of data retention at room temperature. Therefore, MRAM can be considered to be an excellent solution for the Gamma module register in the OLED drive circuit. The working principle of MRAM is to apply a horizontal current to the material layer with strong spin-orbit interaction at the bottom of the MTJ (megnetic-tunnel juction) storage unit, so that the vertically polarized spin current due to the spin Hall effect changes the magnetization direction of the free layer, such as Figure 2 shown.

[0007] a) When the magnetization directions of the free layer and the reference layer are the same, the entire device is in a parallel state, and the entire MRAM is in a low resistance state, which can be used as a write "0" state;

[0008] b) When the magnetization directions of the free layer and the reference layer are opposite, the entire device is in an anti-parallel state, and the entire MRAM is in a high-resistance state, which can be used as a write "1" state;

[0009] c) OTP (one time programmable) devices, that is, one-time programmable devices, belong to non-volatile memory.

[0010] The register of the existing Gamma calibration circuit generally adopts OTP circuit, which includes control circuit and memory. Among them, the core part is an embedded one time programmable memory, which can only be burned once, but can be read multiple times. The OTP circuit module is generally based on traditional CMOS process devices, and its main device working principles are divided into two types: based on fuse (Fuse) implementation and based on anti-fuse (Anti-fuse) implementation. The former (Fuse) applies high-density current through I / O voltage, and the low-resistance metal (generally silicide metal) in the efuse is electro-migrated and melted due to high-density current passing through narrow metal wires or polysilicon, but it has the disadvantages of high power consumption, slow speed, and few erasable times. The latter (Anti-fuse) applies high voltage through a thin gate to break down the gate oxide or applies high voltage between the source and drain to produce avalanche breakdown and other effects, so that the MOSFET is permanently in a low-resistance state, thereby storing data, but the power consumption is high, the speed is slow, and over time, the breakdown of the MOSFET will produce partial self-repair, resulting in data loss and errors.

[0011] The OTP storage unit in the existing gamma correction circuit, whether using the fuse or anti-fuse working mode, is destructive and irreversible in order to achieve its basic non-volatile function from the working principle of the device, and cannot meet the realization of subsequent multiple gamma calibration functions. Summary of the invention

[0012] In order to achieve the above-mentioned purpose and other advantages according to the present invention, the first purpose of the present invention is to provide an MRAM-based OLED driver chip Gamma correction circuit, including an MRAM storage logic control circuit, a grayscale detection circuit, a resistor selection circuit, a differential amplifier circuit, a grayscale voltage divider circuit, and an OLED pixel driving circuit; wherein,

[0013] The MRAM storage logic control circuit is used to read data in the MRAM storage array and store new calibration data in the MRAM storage array;

[0014] The resistance selection circuit is used to select a corresponding voltage;

[0015] The grayscale detection circuit is used to generate a power-on self-test voltage signal;

[0016] The differential amplifier circuit is used to compare and calibrate the voltage selected by the resistance selection circuit with the power-on self-test voltage signal generated by the grayscale detection circuit;

[0017] The grayscale voltage divider circuit is used to convert the calibrated signal into a voltage signal;

[0018] The OLED pixel driving circuit is used to adjust the voltage of the OLED pixel driving through the voltage signal, and transmit the calibrated voltage signal to the MRAM storage logic control circuit.

[0019] Furthermore, the MRAM storage logic control circuit includes an address decoder, a control logic module, a read circuit, a write circuit, an MRAM storage array and a data port; the MRAM storage array includes a plurality of storage cells; wherein,

[0020] The address decoder is used to store all address decoding inside the OLED driver chip;

[0021] The control logic module is used to generate a control signal to control the read and write operations of the MRAM storage array;

[0022] The read circuit is used to read the stored data, identify the storage value of the selected storage unit, and transmit the data to the data port;

[0023] The write circuit is used to transmit the external high-voltage circuit signal to the selected storage unit bit line to perform a write operation on the selected storage unit;

[0024] The MRAM storage array is used to store data signals;

[0025] The data port is used to input write data and output read data.

[0026] Furthermore, according to the distribution of the MRAM storage array, the address decoder is divided into a block selection decoder, a row selection decoder and a column selection decoder.

[0027] Furthermore, the write circuit uses the MOS tube on the write bit line to generate current to flip the magnetic direction of the ferromagnetic layer of the storage unit, so that the resistance of the storage unit changes and the resistance is maintained after power failure, thereby achieving the function of writing and maintaining data.

[0028] Furthermore, the data port is a bidirectional data port.

[0029] A second object of the present invention is to provide a correction method for a gamma correction circuit of an OLED driver chip based on MRAM, comprising the following steps:

[0030] S1. Measure the current OLED grayscale brightness and coordinate range;

[0031] S2, reading the Gamma storage value pre-stored in the MRAM storage array or the last calibration result through the reading circuit, and performing a correction operation on the grayscale brightness and coordinates of the current OLED;

[0032] S3, adjusting the driving circuit voltage according to the result of the correction operation and the relationship between the voltage and the brightness, reading and writing the MRAM storage array, so as to achieve the effect of correcting the OLED light emitting brightness;

[0033] S4, measuring the grayscale brightness and coordinate range of the calibrated OLED to determine whether it meets the expected display effect;

[0034] S5. If the expected display effect is met, the current Gamma calibration value is stored in the MRAM storage array through the writing circuit, so as to be directly called when the computer is turned on next time;

[0035] S6. If the expected display effect is not met, recalculate according to the current grayscale brightness and coordinate range, correct the value table in the Gamma register, and then repeat steps S2 and S3 until the expected display effect is achieved;

[0036] S7. The result information of this correction is stored in a corresponding memory for subsequent testing and OLED product quality grading.

[0037] Furthermore, the S2 step includes:

[0038] Power on the MRAM program / erase pins;

[0039] Power on the high voltage power pin of the MRAM;

[0040] Prepare the data to be written in the data line of the MRAM;

[0041] Pull up the read control pin of MRAM and wait for data output;

[0042] Turn off the high voltage power pin;

[0043] Turn off the program / erase pin.

[0044] Furthermore, the S3 step includes:

[0045] Convert digital quantity to analog quantity through digital-to-analog converter;

[0046] After the high voltage power supply pin and programming / erase pin of the MRAM complete the power-on operation, the write control pin of the MRAM is pulled up to a high potential, the MRAM enters the write state, the data line of the MRAM is ready for the written data, the write data is written through the write data line of the MRAM, and the read control pin of the MRAM enters a high potential to output the written data.

[0047] The third object of the present invention is to provide an electronic device, comprising: a memory on which a program code is stored; a processor, which is connected to the memory and when the program code is executed by the processor, a correction method for a gamma correction circuit of an OLED driver chip based on MRAM is implemented.

[0048] A fourth object of the present invention is to provide a computer-readable storage medium having program instructions stored thereon, wherein when the program instructions are executed, a correction method for a gamma correction circuit of an OLED driving chip based on MRAM is implemented.

[0049] Compared with the prior art, the present invention has the following beneficial effects:

[0050] The gamma correction circuit in the OLED driving chip of the present invention adopts MRAM as a storage unit, which not only has the ability to store data when the power is off, but also has low energy consumption and high speed for reading and writing, and greatly improves the reliability of data storage.

[0051] Compared with the traditional OTP memory, the present invention uses MRAM as the storage unit, which has the ability to be repeatedly erased and written. Therefore, the correction circuit can fine-tune the Gamma numerical parameters multiple times, more accurately control the OLED voltage, improve the display effect and extend the service life.

[0052] The present invention can reduce the chance of incorrect Gamma calibration of OLED, and OLED has the opportunity to be retested and calibrated at any time, thereby reducing the cost of error risk.

[0053] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. The specific implementation of the present invention is given in detail by the following embodiments and their accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0055] Figure 1 This is a common Gamma chip circuit system block diagram;

[0056] Figure 2 This is the schematic diagram of the MRAM device;

[0057] Figure 3 This is a schematic diagram of a gamma correction circuit of an OLED driver chip based on MRAM according to Example 1;

[0058] Figure 4 This is a schematic diagram of the MRAM storage logic control circuit of Example 1;

[0059] Figure 5 This is a flow chart of a correction method for a Gamma correction circuit of an OLED driving chip based on MRAM according to Example 2;

[0060] Figure 6 Schematic diagram of the MRAM chip of Example 2;

[0061] Figure 7 This is a timing diagram of the MRAM data reading process of Example 2;

[0062] Figure 8 This is a timing diagram of the MRAM data writing process of Example 2;

[0063] Fig. 9 This is a schematic diagram of an electronic device according to Embodiment 3;

[0064] Fig.10 This is a schematic diagram of a computer-readable storage medium of Example 4. DETAILED DESCRIPTION

[0065] The present invention is further described below in conjunction with the accompanying drawings and specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form a new embodiment.

[0066] The existing OTP memory is widely used as a data storage module in the Gamma calibration circuit of the OLED driver chip circuit because of its non-volatile characteristics that data will not be lost in the event of power failure. However, due to its slow writing speed, high energy consumption, lack of stability and reliability of data retention, and similar destructive data storage mechanism, that is, data can only be entered once, it cannot meet the functional requirements of multiple Gamma corrections. Therefore, the present invention adopts a new storage device MRAM as the memory of the Gamma correction circuit, which can further improve the writing and reading speed of the Gamma correction, while reducing power consumption and improving stability. And by utilizing the characteristic that MRAM can be erased and written multiple times, the present invention correspondingly proposes a new Gamma correction circuit that can perform repeated calibration multiple times, further improving the life and display quality of the OLED.

[0067] Example 1

[0068] Gamma correction circuit of OLED driver chip based on MRAM, such as Figure 3 As shown, it includes an MRAM storage logic control circuit, a grayscale detection circuit, a resistor selection circuit, a differential amplifier circuit, a grayscale voltage divider circuit, and an OLED pixel driving circuit; wherein,

[0069] The MRAM storage logic control circuit is used to read the data in the MRAM storage array and store new calibration data in the MRAM storage array for reading at the next power-on.

[0070] The resistance selection circuit is used to select the corresponding voltage size;

[0071] The grayscale detection circuit is used to generate a power-on self-test voltage signal;

[0072] The differential amplifier circuit is used to compare and calibrate the voltage selected by the resistor selection circuit with the power-on self-test voltage signal generated by the grayscale detection circuit;

[0073] The grayscale voltage divider circuit is used to convert the calibrated signal into a voltage signal;

[0074] The OLED pixel driving circuit is used to adjust the voltage of the OLED pixel driving through the voltage signal, and transmit the calibrated voltage signal to the MRAM storage logic control circuit.

[0075] like Figure 4 As shown, the MRAM storage logic control circuit includes an address decoder, a control logic module, a read circuit, a write circuit, an MRAM storage array and a data port; the MRAM storage array includes a plurality of storage cells; wherein,

[0076] The address decoder is used to store all address decoding inside the OLED driver chip; according to the distribution of the MRAM storage array, the address decoder is divided into a block select decoder, a row select decoder and a column select decoder, which respectively control the block, row and column addressing of the MRAM.

[0077] The control logic module is used to generate control signals to control the read and write operations of the MRAM storage array; it mainly includes an address detection circuit, a pulse expansion circuit, a high-voltage discharge circuit and some combinational logic control circuits.

[0078] The read circuit is used to read the stored data, identify the storage value of the selected storage unit, and transmit the data to the data port; it mainly includes a sensitive amplifier and a sampling latch circuit.

[0079] The write circuit is used to transmit the external high-voltage circuit signal to the selected storage unit bit line and perform a write operation on the selected storage unit; specifically, the write circuit uses the MOS tube on the write bit line to generate current, flip the magnetic direction of the ferromagnetic layer of the storage unit, and the resistance value of the storage unit changes, and the resistance value is still maintained after power failure, thereby achieving the function of writing data and maintaining it.

[0080] The MRAM storage array is used to store data signals, and mainly has data read / write capabilities and a non-volatile data retention function.

[0081] The data port is used to input write data and output read data. In this embodiment, the data port is a bidirectional data port.

[0082] Example 2

[0083] The correction method of the Gamma correction circuit of the MRAM-based OLED driver chip of Example 1 is as follows: Figure 5 As shown, the following steps are included:

[0084] S1. Measure the current OLED grayscale brightness and coordinate range after powering on; Figure 6 The schematic diagram of the 128*8bit MARM chip is shown in Figure 1. Vss is the node port, VDD is the high voltage power supply pin of the memory, which generally needs to be filled with high voltage during MRAM storage, and is left floating or the same voltage as VDD during MRAM reading; PA is the data line; PDIN is the write data line; PPROG is the programming control pin; PRD is the read control pin; VDD is the high voltage power supply pin; Vss is the low voltage power supply pin; and VPP is the programming / erase pin.

[0085] S2, read the Gamma storage value of the factory pre-stored or last calibration result in the MRAM storage array through the reading circuit, and perform correction calculation on the grayscale brightness and coordinates of the current OLED; the reading process of the MRAM is as follows Figure 7 Specifically, the programming / erase pin VPP of the MRAM is powered by 1.8V; the high voltage power pin VDD of the MRAM is powered by 1.8V; the data [6:0] to be written in the data line PA of the MRAM is prepared; the read control pin PRD of the MRAM is pulled high, and the PDOB data is waited for output; the high voltage power pin VDD is turned off; and the programming / erase pin VPP is turned off.

[0086] S3, according to the result of the correction operation, and the relationship between voltage and brightness, the driving circuit voltage is adjusted, and the MRAM storage array is read and written to achieve the effect of correcting the OLED light brightness; the writing process of the MRAM is as follows Figure 8 Specifically, the digital quantity is converted to the analog quantity through a digital-to-analog converter (DAC); after the high voltage power pin VDD and the programming / erase pin VPP of the MRAM complete the power-on operation, the MRAM programming control pin PPRGO is pulled up to a high potential, the MRAM is in a writing state, the MRAM data line PA is ready for the written data, the written data is written through the MRAM write data line PDIN, the MRAM read control pin PRD enters a high potential, and the written data is output by PDOB.

[0087] S4, measuring the grayscale brightness and coordinate range of the calibrated OLED to determine whether it meets the expected display effect;

[0088] S5. If the expected display effect is met, the current Gamma calibration value is stored in the MRAM storage array through the writing circuit, so as to be directly called when the computer is turned on next time;

[0089] S6. If the expected display effect is not met, recalculate according to the current grayscale brightness and coordinate range, correct the value table in the Gamma register, and then repeat steps S2 and S3 until the expected display effect is achieved;

[0090] S7, the result information of this correction is stored in the corresponding memory for subsequent testing and OLED product quality grading. This Gamma calibration process is completed. The result information includes the number of modifications and the modified Gamma value.

[0091] Compared with the traditional Gamma process using OTP memory, the present invention uses MRAM as the Gamma memory, which not only has the power-off data retention function of the OTP memory, but also because the MRAM has the characteristic of being repeatedly erasable and rewritable, the numerical parameters in the Gamma memory can be fine-tuned. Therefore, the Gamma circuit of the present invention has the ability of multiple calibrations, which can not only improve the precise control of the OLED brightness, but also can make multiple adjustments considering the aging of the OLED, thereby increasing the service life of the OLED.

[0092] It should be noted that since the MRAM memory manufacturing process is compatible with the traditional CMOS circuit process, it can be designed and manufactured into a SOC chip, which can reduce the chip area and better reduce the delay between modules.

[0093] According to the market segmentation needs of OLED driver chips, manufacturing processes at different technology nodes can be adopted to achieve the goal of balancing performance and cost.

[0094] Example 3

[0095] An electronic device, such as Fig. 9 As shown, it includes: a memory on which program codes are stored; a processor connected to the memory, and when the program codes are executed by the processor, a correction method for a gamma correction circuit of an OLED driver chip based on MRAM is implemented. For a detailed description of the method, reference may be made to the corresponding description in the above method embodiment, which will not be repeated here.

[0096] Example 4

[0097] A computer readable storage medium such as Fig.10 As shown, program instructions are stored thereon, and when the program instructions are executed, a correction method for the Gamma correction circuit of the OLED driver chip based on MRAM is implemented. For a detailed description of the method, reference may be made to the corresponding description in the above method embodiment, and no further description is given here.

[0098] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0099] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0100] The above are only embodiments of this specification and are not intended to limit one or more embodiments of this specification. For those skilled in the art, one or more embodiments of this specification may have various changes and transformations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of one or more embodiments of this specification shall be included in the scope of the claims of one or more embodiments of this specification. One or more embodiments of this specification One or more embodiments of this specification One or more embodiments of this specification One or more embodiments of this specification.

Claims

1. An MRAM-based OLED driver chip Gamma correction circuit, characterized in that: It includes an MRAM storage logic control circuit, a grayscale detection circuit, a resistor selection circuit, a differential amplifier circuit, a grayscale voltage divider circuit, and an OLED pixel drive circuit; wherein, The MRAM storage logic control circuit is used to read data in the MRAM storage array and store new calibration data in the MRAM storage array; The resistance selection circuit is used to select a corresponding voltage; The grayscale detection circuit is used to generate a power-on self-test voltage signal; The differential amplifier circuit is used to compare and calibrate the voltage selected by the resistance selection circuit with the power-on self-test voltage signal generated by the grayscale detection circuit; The grayscale voltage divider circuit is used to convert the calibrated signal into a voltage signal; The OLED pixel driving circuit is used to adjust the voltage of the OLED pixel driving through the voltage signal, and transmit the calibrated voltage signal to the MRAM storage logic control circuit; The MRAM storage logic control circuit includes an address decoder, a control logic module, a read circuit, a write circuit, an MRAM storage array and a data port; the MRAM storage array includes a plurality of storage cells; wherein, The address decoder is used to store all address decoding inside the OLED driver chip; The control logic module is used to generate a control signal to control the read and write operations of the MRAM storage array; The read circuit is used to read the stored data, identify the storage value of the selected storage unit, and transmit the data to the data port; The write circuit is used to transmit the external high-voltage circuit signal to the selected storage unit bit line to perform a write operation on the selected storage unit; The MRAM storage array is used to store data signals; The data port is used to input write data and output read data.

2. The MRAM-based OLED driver chip gamma correction circuit according to claim 1, characterized in that: According to the distribution of the MRAM storage array, the address decoder is divided into a block selection decoder, a row selection decoder and a column selection decoder.

3. The MRAM-based OLED driver chip gamma correction circuit according to claim 1, characterized in that: The write circuit uses the MOS tube on the write bit line to generate current to flip the magnetic direction of the ferromagnetic layer of the storage unit, so that the resistance of the storage unit changes and the resistance is maintained after power failure, thereby achieving the function of writing and maintaining data.

4. The MRAM-based OLED driver chip gamma correction circuit according to claim 1, characterized in that: The data port is a bidirectional data port.

5. A method for correcting a gamma correction circuit of an OLED driver chip based on MRAM, which realizes correcting the gamma correction circuit of an OLED driver chip based on MRAM as claimed in claim 1, characterized in that: The following steps are involved: S1. Measure the current OLED grayscale brightness and coordinate range; S2, reading the Gamma storage value pre-stored in the MRAM storage array or the last calibration result through the reading circuit, and performing a correction operation on the grayscale brightness and coordinates of the current OLED; S3, adjusting the driving circuit voltage according to the result of the correction operation and the relationship between the voltage and the brightness, reading and writing the MRAM storage array, so as to achieve the effect of correcting the OLED light emitting brightness; S4, measuring the grayscale brightness and coordinate range of the calibrated OLED to determine whether it meets the expected display effect; S5. If the expected display effect is met, the current Gamma calibration value is stored in the MRAM storage array through the writing circuit, so as to be directly called when the computer is turned on next time; S6. If the expected display effect is not met, recalculate according to the current grayscale brightness and coordinate range, correct the value table in the Gamma register, and then repeat steps S2 and S3 until the expected display effect is achieved; S7. The result information of this correction is stored in a corresponding memory for subsequent testing and OLED product quality grading.

6. The correction method of the Gamma correction circuit of the MRAM-based OLED driver chip according to claim 5, characterized in that: The S2 step includes: Power on the MRAM program / erase pins; Power on the high voltage power pin of the MRAM; Prepare the data to be written in the data line of the MRAM; Pull up the read control pin of MRAM and wait for data output; Turn off the high voltage power pin; Turn off the program / erase pin.

7. The correction method of the Gamma correction circuit of the MRAM-based OLED driver chip according to claim 6, characterized in that: The S3 step includes: Convert digital quantity to analog quantity through digital-to-analog converter; After the high voltage power supply pin and programming / erase pin of the MRAM complete the power-on operation, the write control pin of the MRAM is pulled up to a high potential, the MRAM enters the write state, the data line of the MRAM is ready for the written data, the write data is written through the write data line of the MRAM, and the read control pin of the MRAM enters a high potential to output the written data.

8. An electronic device, characterized in that: include: A memory having program code stored therein; A processor is coupled to the memory and implements the method according to any one of claims 5 to 7 when the program code is executed by the processor.

9. A computer-readable storage medium, characterized in that: Program instructions are stored thereon, and when the program instructions are executed, the method according to any one of claims 5 to 7 is implemented.

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