CN101377919B - gamma correction device - Google Patents

Abstract

A gamma correction device comprises a loading control unit, a Read Only Memory (ROM), a Static Random Access Memory (SRAM), a check code unit and a counting unit. The read-only memory is used for storing a plurality of gamma data and a check code. The static memory is coupled with the read-only memory and used for storing data. And the loading control unit is used for controlling the loading action of loading the plurality of gamma data in the read-only memory to the static memory. The check code unit is used for receiving and judging whether the gamma data in the static memory have errors according to the check code. The counting unit is used for accumulating the times of the error detected by the check code unit. When the check code unit checks errors, the loading control unit reloads the plurality of gamma data from the read-only memory into the static memory.

Description

Gamma correction device

technical field

The present invention relates to a gamma correction device, and in particular to a gamma correction device capable of preventing electrostatic discharge (Electrostatic Discharge, ESD) effects and memory process defects. the

Background technique

In today's era of rapid technological development, gamma correction (Gamma Correction) has been widely used in image display occasions, so that the display effect of the image is more in line with the visual psychological perception of the human eye. When gamma correction is to be performed on the original image, it is through a predetermined gamma curve, for example:

$\mathrm{gray}\_\mathrm{out}=\mathrm{gray}\_\max \×{\left(\frac{\mathrm{gray}\_\mathrm{in}}{\mathrm{gray}\_\max }\right)}^{\mathrm{\γ}}$ The corresponding output gray-scale value gray_out is generated by mapping according to the gamma value γ, the input gray-scale value gray_in and the highest gray-scale value gray_max.

In the prior art, the gamma correction curve is stored as a look-up table, and when the gamma correction unit intends to perform gamma correction, it loads the look-up table into the memory for gamma correction. However, the look-up table data in the memory is prone to errors due to external interference, such as electrostatic discharge (Electrostatic Discharge, ESD), which further degrades the gamma correction effect and even generates errors. the

Contents of the invention

The present invention provides a gamma correction (Gamma Correction) device, which can effectively improve the shortcomings of traditional gamma correction devices that are easily affected by electrostatic discharge (Electrostatic Discharge, ESD) and gamma correction results are prone to errors, and essentially The operation of the gamma correction device can be effectively prevented from being affected by the electrostatic discharge effect and its operation can be terminated when the gamma correction device is permanently damaged, so as to enhance the advantages of its gamma correction accuracy. the

According to the present invention, a gamma correction device is proposed, including: a load control unit, a read only memory (Read Only Memory, ROM), a static memory (Static Random Access Memory, SRAM), a check code unit and a counting unit. A read-only memory, used to store a plurality of gamma data and a check code; a static memory, coupled to the read-only memory, for storing data; a loading control unit, used to control the gamma in the read-only memory The loading action of loading data into the static memory; the check code unit is used to receive and judge whether the gamma data in the static memory has errors according to the check code; the counting unit is used to accumulate the check code unit for continuous checking the number of errors; where, when the check code unit detects an error, the load control unit reloads the gamma data from the read-only memory into the static memory. the

In order to make the above-mentioned content of the present invention more comprehensible, a preferred embodiment is specifically cited below, together with the accompanying drawings, and described in detail as follows. the

Description of drawings

FIG. 1 shows a block diagram of a gamma correction device according to an embodiment of the present invention. the

FIG. 2 shows a schematic diagram of the check code unit 18 in FIG. 1 . the

Description of reference symbols

10: Gamma correction device

12: Load control unit

14: read-only memory

16: static memory

18: check code unit

20: counting unit

22: Logic unit. the

Detailed ways

Please refer to FIG. 1 , which shows a block diagram of a gamma correction device according to an embodiment of the present invention. The gamma correction device 10 is applied to a display system to perform gamma correction on an input gray scale value (not shown), so that the display system can have a better display effect. The gamma correction device 10 includes a load control unit 12 , a read-only memory 14 , a static memory 16 , a check code unit 18 and a counting unit 20 . The load control unit 12 respectively provides the address signal Sad and the write signal Swr to the ROM 14 and the static memory 16 to control the loading operation of gamma data in the ROM 14 to the static memory. the

The read-only memory 14 is used to store a plurality of gamma data Sda and the check code Sch, and provide the gamma data Sda and the check code Sch stored in the corresponding address according to the address signal Sad. The static memory 16 receives and stores the gamma data Sda according to the write signal Swr, and stores the gamma data Sda in a corresponding address in the static memory 16 according to the address signal Sad. the

The gamma data Sda is, for example, substantially used to represent a corresponding gamma curve for mapping an input gray scale value (not shown) to the corresponding gamma data Sda and outputting it. When the gamma data Sda is loaded, the static memory 16 can map the input gray scale value to the corresponding gamma data for corresponding gamma correction. the

The check code unit 18 is used to receive and operate according to the gamma data Sda stored in the static memory 16 to obtain an operation value (not shown). The check code unit further receives and compares whether the check code Sch is equal to the operation value to determine whether the gamma data Sda stored in the gamma memory 16 is correct. Wherein, the check code unit 18 is, for example, a traditional cyclic redundancy check code (Cyclic Redundancy Check, CRC) check code unit, a schematic diagram of which is shown in FIG. 2 . In this embodiment, when the operation value calculated by the check code unit 18 is equal to the check code Sch, it means that the gamma data Sda has no error; if the operation value is not equal to the check code Sch, it means that the gamma Data contains errors. The counting unit 20 is used to accumulate the number of times that the check code unit 18 continuously checks out errors or calculates the number of times of repeated loading n, and when the check code Sch is not equal to the operand value, the number of times of repeated loading n=n+1 is accumulated, and n is greater than or equal to Integer of 0. Wherein, whenever the check code unit 18 judges that the gamma data of the static memory 16 is correct, the accumulated value of the counting unit is reset, which means that the accumulated value accumulated by the counting unit is reset to zero. the

The loading control unit 12 is further configured to reload the gamma data in the ROM 14 into the static memory 16 when the checksum unit 18 determines that the gamma data has errors. In this way, the gamma correction device 10 of this embodiment can automatically re-execute the loading operation when the gamma data Sda loaded by the static memory 16 is incorrect. In this way, the gamma correction device 10 of this embodiment can effectively prevent the operation of the gamma correction device from being affected by occasional external interference, such as electrostatic discharge (Electrostatic Discharge, ESD), which will cause errors in the gamma correction. the

For example, the check code unit 18 generates a completion signal Sfi when the operation of comparing the check code Sch with the operand value is completed, and generates an output signal Sou when the check code Sch is equal to the operand value. The counting unit 20, for example, responds to the completion signal Sfi and the output signal Sou to determine whether the check code Sch is equal to the operation value. When the counting unit 20 receives the completion signal Sfi and the output signal Sou, it means that the check code Sch is equal to the operation value. the

When the counting unit 20 receives the completion signal Sfi but does not detect the output signal Sou, it means that the check code Sch is not equal to the operation value, that is, the gamma data Sda in the static memory 16 is wrong, and the counting unit 20 accumulates and repeats at this time Loading times n=n+1. the

When the repeated loading times n calculated by the counting unit 20 exceeds a preset value, the counting unit 20 generates a termination signal Stm to shut down the loading control unit 12 , the static memory 16 and the checksum unit 18 . In this way, the gamma correction device 10 is turned off to terminate its gamma correction operation, wherein the preset value is a natural number greater than 1. the

When the number of times of repeated loading exceeds the preset value, it means that the gamma correction device 10 is substantially permanently damaged, for example, the static memory 16 has a process defect (Process Defect) or the storage unit (Cell) of the static memory 16 after long-term use Corruption occurs, causing the gamma data Sda therein to be continuously wrong. At this time, the gamma correction device 10 of the present embodiment terminates its gamma correction operation through the termination signal Stm. In this way, the gamma correction device 10 of this embodiment can effectively stop its gamma correction when the hardware therein is permanently damaged, so as to avoid affecting the display effect of the display system. the

The load control unit 12 can judge whether the check code Sch and the operation value are equal according to the output signal Sou, and provide the address signal Sad and the write signal Swr to drive the static memory 16 to load the gamma data in the read-only memory 14 when they are not equal. Sda. the

In one embodiment, the load control unit 12 includes a logic unit (not shown), which is used to provide the address signal Sad and write when a reset signal Sre is received or an output signal Sou is not detected. The signal Swr drives the SRAM 16 to load the gamma data Sda in the ROM 14 . The logic unit of this embodiment is, for example, a NOR gate (NOR), which is used to respond to the low level of the reset signal Sre and the output signal Sou to respectively determine the corresponding event as a trigger, and when any corresponding event triggers , the gamma data in the read-only memory 14 is reloaded into the static memory 16 . the

The gamma correction device 10 of this embodiment further includes a logic unit 22 for receiving and providing the check code Sch provided by the ROM 14 to the check code unit 18 in response to the address signal Sad. the

The gamma correction device of this embodiment compares the operation data of the gamma data with the check code by the check code unit, and controls the gamma correction device to reload the gamma data to the static memory when the obtained comparison result is different. In this way, the gamma correction device of this embodiment can effectively improve the shortcomings of traditional gamma correction devices that are easily affected by the electrostatic discharge effect and the gamma correction results are prone to errors, and can effectively avoid the operation of the gamma correction device The advantage of being affected by electrostatic discharge effects and its gamma correction correctness. the

In addition, the gamma correction device of this embodiment further uses the counting unit to judge whether the gamma data in the static memory has multiple load errors consecutively, and judges the gamma data when the gamma data in the static memory is continuously wrong for a predetermined number of times. Permanent damage to the horse correction mechanism shuts down the gamma correction system. In this way, the gamma correction device of this embodiment has the advantage of being able to effectively determine and prevent damage to the gamma correction device from affecting its gamma correction accuracy. the

In summary, although the present invention has been disclosed as above with a preferred embodiment, it is not intended to limit the present invention. Those skilled in the art of the present invention can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be defined by the patent scope of the present invention. the

Claims (8)

1. A gamma correction device, comprising: A read-only memory for storing multiple pieces of gamma data and a check code; a static memory, coupled to the read-only memory, for storing data; a loading control unit, used to control the loading action of loading the gamma data in the read-only memory to the static memory; a check code unit for receiving and judging whether the gamma data in the static memory has errors according to the check code; and A counting unit for accumulating the number of times the check code unit detects errors continuously; Wherein, when the check code unit detects an error, the load control unit reloads the gamma data from the read-only memory into the static memory. 2. The gamma correction device according to claim 1, wherein the check code unit operates the gamma data in the static memory to obtain an operation value, and then compares the check code with the operation value to obtain It is judged whether the gamma data has an error. 3. The gamma correction device as claimed in claim 2, wherein the check code unit is used to generate a completion signal when the operation of comparing whether the check code is equal to the operation value is completed, and the check code unit is further used to When the comparison result is that the check code is equal to the operation value, an output signal is generated. 4 . The gamma correction device according to claim 3 , wherein the counting unit counts the number of times the check code unit detects errors continuously according to the completion signal and the output signal. 5. The gamma correction device as claimed in claim 1, wherein, when the cumulative value of the counting unit's accumulative number of consecutively detected errors is greater than a preset value, the gamma correction device will load the control unit, the static memory And the checksum unit is disabled. 6 . The gamma correction device according to claim 1 , wherein whenever the check code unit judges that the gamma data in the static memory is correct, the accumulated value accumulated by the counting unit is reset to zero. 7. The gamma correction device as claimed in claim 1, wherein the load control unit loads the gamma data in the read-only memory into the static memory through an address signal and a write signal. 8. The gamma correction device as claimed in claim 1, further comprising: A logic unit is used for providing the check code of the ROM to the check code unit according to the address signal.

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