TWI433097B - Display apparatus, display controller and operating method thereof - Google Patents

Description

Display, display controller and operation method of the display controller

This invention relates to a display and, more particularly, to a display controller.

1 is a functional block diagram illustrating a conventional display. Referring to FIG. 1 , the electronic system 100 includes a host 110 and a display 120 . Depending on the application system, host 110 can be a different type of processor, controller, or computer. For example, if the electronic system 100 is applied to a mobile phone system, the host 110 can be a baseband processor. If the electronic system 100 is applied to a monitor system, the host 110 can be a monitor controller. If the electronic system 100 is applied to a notebook computer system, the host 110 may be a display processor or a graphics processing unit (GPU).

The display 120 includes a controller 130 and a display module 140. The display module 140 includes a gate driver 141, a source driver 142, and a display panel 143. By transmitting the display data D to the controller 130, the host 110 can cause the host 110 to output a series of original frames to the controller 130 at a frequency of 60 Hz or 75 Hz. Since the host 110 provides a series of original frames to the controller 130 on time and without interruption, the controller 130 can display the original frames on the display panel 143 through the source driver 142 without temporarily storing the original provided by the host 110. frame. That is, regardless of the host 110 Whether the original frame provided is a still frame (still frame), the display data D is continuously transmitted between the controller 130 and the host 110. However, when the original frame provided by the host 110 is a still frame, that is, the host 110 provides a series of original frames that are the same display data, the original frame with the same display data is repeatedly transmitted between the controller 130 and the host 110. . Obviously, the original frame having the same display material is repeatedly transmitted between the controller 130 and the host 110, and this operation behavior is redundant and very power-consuming.

The present invention provides a display, a display controller, and a method of operating the display controller. When the original frame provided by the host is a still frame, the display can perform self refresh. When the display is self-updating, there is no need to transfer display data between the controller and the host to reduce power consumption.

Embodiments of the present invention provide a display controller including a controller, a buffer, and a compression and decompression unit. The controller receives the original frame from the host. The controller controls the display module to display the original frame provided by the host in the non-stationary frame mode. The compression and decompression unit is coupled between the buffer and the controller. The controller compresses the original frame to the buffer through the compression and decompression unit. Wherein, if the controller operates in the still frame mode, the controller decompresses the compressed frame of the buffer through the compression and decompression unit to obtain the decompressed frame, and controls the display module to display the decompressed frame.

An embodiment of the present invention provides a method for operating a display controller, including: receiving an original frame from a host; compressing the original frame to obtain a compressed frame; storing the compressed frame in a buffer; and in a non-stationary frame mode Controlling a display module to display the original frame provided by the host; and if in the still frame mode, decompressing the compressed frame to obtain a decompressed frame, and controlling the display module to display the decompressed frame .

Embodiments of the present invention provide a display including a display module, a controller, a buffer, and a compression and decompression unit. The controller is connected to the display module. The controller receives the original frame from the host. The controller controls the display module to display the original frame provided by the host in the non-stationary frame mode. The compression and decompression unit is coupled between the buffer and the controller. The controller compresses the original frame to the buffer through the compression and decompression unit. Wherein, if the controller operates in the still frame mode, the controller decompresses the compressed frame of the buffer through the compression and decompression unit to obtain a decompressed frame, and controls the display module to display the decompressed frame.

Based on the above, the host disclosed in the embodiment of the present invention can determine whether the current original frame is a still frame. When the current original frame is a still frame, the host can trigger the controller of the display to enter the still frame mode to compress the original frame to the buffer, so the present invention can use a buffer having a smaller capacity than the original frame to reduce the hard Body cost. After successfully compressing the original frame to the buffer, the display data can be stopped between the controller and the host. At this time, the display can perform self-updating, that is, the controller decompresses the compressed frame of the buffer through the compression and decompression unit to obtain the decompressed frame, and controls the display module to display the decompressed frame. On the display When I update, the display data can be transmitted between the controller and the host. Therefore, the display and display controller disclosed in the embodiments of the present invention can reduce power consumption.

The above described features and advantages of the present invention will be more apparent from the following description.

2 is a functional block diagram illustrating an embodiment of a display. Referring to FIG. 2, the electronic system 200 includes a host 110 and a display 220. For the implementation of the host 110, reference may be made to the related description of FIG. The display 220 includes a display module 140 and a display controller, wherein the display controller includes a controller 230 and a frame buffer 250. The display module 140 includes a gate driver 141, a source driver 142, and a display panel 143. By transmitting the display material D to the controller 230, the host 110 can output a series of original frames to the controller 230 at 60 Hertz (Hz), 75 Hz, or other frequencies.

The host 110 performs motion detection to determine whether the original frame currently provided is a still frame (still picture), and outputs a self-update enable signal SRE to the controller 230 according to the result of the motion detection. The controller 230 determines whether to operate in the "non-stationary frame mode" or the "still frame mode" based on the self-update enable signal SRE. If the result of the motion detection indicates that the original frame currently provided is not a still frame, the self-update enable signal SRE is in a disabled state (for example, a low logic level), so that the controller 230 operates on the "non-stationary frame". mode". Non-stationary frame mode In the formula, the host 110 transmits a series of original frames to the controller 230 on time and without interruption through the transmission of the display data D. The controller 230 can display the original frame provided by the host 110 to the display panel 143 through the source driver 142.

If the result of the motion detection performed by the host 110 indicates that the original frame currently provided is a still frame, the self-update enable signal SRE is in an enable state (for example, a high logic level), so that the controller 230 operates on "Still Frame Mode". In this still frame mode, the host 110 stores the original frame in the frame buffer 250 through the controller 230 in a memory addressing mode. The capacity of the frame buffer 250 must be equal to or greater than the amount of data of the original frame in order to save the entire original frame. After the original frame is stored in the frame buffer 250, the display of the display material D can be stopped between the controller 230 and the host 110. At this point, display 220 may perform a self refresh, ie controller 230 obtains the original frame from frame buffer 250 and controls display module 140 to display the original frame provided by frame buffer 250.

When the display 220 performs self-updating, the display data D can be stopped between the controller 230 and the host 110. Therefore, the electronic system 200 and the display 220 disclosed in the embodiment can reduce power consumption. In contrast to Figure 1, display 220 in the embodiment of Figure 2 requires configuration of a frame buffer 250 sufficient to hold an entire original frame. As the frame resolution increases, the capacity of the frame buffer 250 must be increased accordingly. For example, if the original frame has a frame resolution of 1920×1080 pixels and each pixel has three 8-bit sub-pixel data, the frame buffer 250 must have at least a capacity. There are 1920 × 1080 × 3 × 8bit = 48600Kbit.

FIG. 3 is a block diagram showing the function of a display according to an embodiment of the invention. Referring to FIG. 3, the electronic system 300 includes a host 110 and a display 320. For the implementation of the host 110, reference may be made to the related description of FIG. The display 320 includes a display module 140 and a display controller, wherein the display controller includes a controller 330, a buffer 350, and a compression and decompression unit 360. The display module 140 can be any type of display panel and drive circuit. For example, the display module 140 includes a gate driver 141, a source driver 142, and a display panel 143. The display module 140 can be well known in the art, and its operational details are not described herein.

Controller 330 can include a timing controller and/or a scaler for display 320. By transmitting the display material D to the controller 330, the host 110 can output a series of original frames to the controller 330. In the case that the original frame is a non-stationary frame, the controller 330 may display the original frame provided by the host 110 to the display panel 143 through the source driver 142.

FIG. 4 is a schematic diagram showing the operation method of the electronic system 300 of FIG. 3 according to an embodiment of the invention. Referring to FIG. 3 and FIG. 4, the host 110 may provide an original frame that is ready to be transmitted to the controller 330 (step S405). The host 110 performs motion detection on the current original frame to determine whether the original frame currently provided is a still frame (step S410), and outputs a self-update enable signal SRE to the controller 330 according to the result of the motion detection. The controller 330 of the display 320 determines whether to operate in "non-stationary frame mode" or "still frame mode" based on the self-update enable signal SRE.

If the result of the motion detection indicates that the original frame currently provided is not a still frame, the host 110 performs step S415 to set the self-update enable signal SRE to the disabled state (for example, set to a low logic level "L"). The controller 330 is caused to operate in the "non-stationary frame mode". In this non-stationary frame mode, the host 110 transmits a series of original frames to the controller 330 of the display 320 on time and without interruption through the transmission of the display material D. The controller 330 operating in the non-stationary frame mode receives the original frame from the host 110 (step S420), and then controls the display module 140 to display the original frame provided by the host 110 (step S425). While the display 320 proceeds to step S425, the host 110 may proceed to steps S405 and S410 to prepare to transmit another original frame to the controller 330 of the display 320.

If the result of the motion detection performed by the host 110 indicates that the original frame currently provided is a still frame, the host 110 performs step S430 to set the self-update enable signal SRE to an enabled state (for example, a high logic level "H" The controller 330 of the display 320 is operated in "still frame mode". In this still frame mode, the host 110 provides the current original frame to the controller 330 of the display 320 by displaying the transmission of the material D. The controller 330 receives the original frame from the host 110 (step S435) and then transmits the original frame to the compression and decompression unit 360. In the present embodiment, the compression and decompression unit 360 includes a compressor 361 and a decompressor 362. Both compressor 361 and decompressor 362 are coupled between buffer 350 and controller 330.

The compressor 361 of the compression and decompression unit 360 proceeds to step S440 to compress the original frame provided by the controller 330 to obtain a compressed frame. And storing the compressed frame to the buffer 350. The compression method utilized by compression and decompression unit 360 can be any form of Lossless Compression algorithm. Since the original frame is compressed and stored in the buffer 350, the capacity of the buffer 350 can be smaller than the amount of data of the original frame. For example, the capacity of the buffer 350 may be 80% or 50% of the amount of the original frame data. Compared to the frame buffer 250 of FIG. 2, the display 320 can employ a smaller capacity buffer 350 to reduce cost.

It is assumed here that the capacity of the buffer 350 is 80% of the amount of the original frame data. The controller 330 can compress the original frame into the buffer 350 through the compression and decompression unit 360. The controller 330 can know whether the size of the compressed frame exceeds the capacity of the buffer 350, that is, the controller 330 can determine the compression and decompression. Unit 360 can successfully compress the original frame to buffer 350 (step S445). If the size of the compressed frame exceeds the capacity of the buffer 350, or the compression and decompression unit 360 cannot compress the original frame to the buffer 350, the controller 330 sets the self-updating flag SRF to the disabled state (eg, setting It is a low logic level "L") (step S450).

In the case that the display 320 cannot compress the original frame to the buffer 350, the controller 330 ends the still frame mode and switches to the non-stationary frame mode to control the display module 140 to display the original frame provided by the host 110. And receiving the next original frame from the host 110. On the other hand, since the self-updating flag SRF is disabled, the host 110 continues to transmit the next original frame to the display 320.

After step S450 is completed, the controller 330 of the display 320 performs steps S420 and S425 again to control the display module 140 to display the host. The original frame provided by 110. At the same time, the host 110 can detect that the display 320 cannot compress the current original frame to the buffer 350 by detecting the self-updating flag SRF, so the host 110 performs steps S405 and S410 again to continue transmitting the next original frame. The display 320 is in an enabled state until the self-renewal enable signal SRE and the self-updating flag SRF.

If the size of the compressed frame does not exceed the capacity of the buffer 350, the compression and decompression unit 360 can successfully compress the original frame to the buffer 350. Therefore, the controller 330 proceeds to step S455 to set the self-updating flag SRF to an enabled state (e.g., set to a high logic level "H"). The host 110 can know that the display 320 has compressed the current original frame to the buffer 350 by detecting the self-updating flag SRF, so the host 110 stops transmitting the display material D to the display 320. That is, when the controller 330 of the display 320 operates in the still frame mode, after the compression and decompression unit 360 successfully compresses the original frame to the buffer 350, the display of the display data D is stopped between the controller 330 and the host 110. .

After completing step S455, the controller 330 operating in the still frame mode will proceed to step S460 to decompress the compressed frame in the buffer 350 through the decompressor 362 of the compression and decompression unit 360, so the controller 330 can A decompressed frame is obtained from buffer 350. In other embodiments, the controller 330 waits for a frame time after completing step S455, and then proceeds to step S460. Since the compression and decompression unit 360 is compressed using distortionless data, the content of the decompressed frame obtained from the buffer 350 is consistent with the content of the original frame provided by the host 110. Next, The controller 330 proceeds to step S465 to control the display module 140 to display the decompressed frame obtained from the buffer 350.

After the display of one frame is completed, the controller 330 of the display 320 checks the state of the self-update enable signal SRE (step S470). If the state of the self-renewal enable signal SRE is the enabled state (for example, set to the high logic level "H"), the controller 330 proceeds to step S460 and step S465 again. If the state of the self-renewal enable signal SRE is disabled (for example, set to a low logic level "L"), indicating that the host 110 detects that the next original frame is not a still frame, the controller 330 ends the still frame mode. And switching to the non-stationary frame mode to receive the next original frame from the host 110, and controlling the display module 140 to display the original frame provided by the host 110.

In the embodiment shown in FIG. 4 above, the controller 330 does not compress the original frame to the buffer 350 when the self-update enable signal SRE is disabled. In other embodiments, the controller 330 may compress the original frame provided by the host 110 to the buffer 350 when the self-update enable signal SRE is enabled, and notify the host 110 of the compression result through the self-updating flag SRF. Therefore, in the case where the display 320 has successfully compressed the original frame to the buffer 350, when the host 110 determines that the original frame currently provided is a still frame, the host 110 sets the self-update enable signal SRE to the enabled state. In addition, the host 110 can also simultaneously stop transmitting the display material D to the controller 330. In the case of the display 320, since the controller 330 has successfully compressed the original frame to the buffer 350 before the self-renewal enable signal SRE transitions to the enabled state, the self-renewal enable signal SRE turns When the state is the enabled state, the controller 330 can perform self-updating immediately (for example, steps S460 and S465 shown in FIG. 4).

FIG. 5 is a block diagram showing the function of an electronic system according to another embodiment of the present invention. Referring to FIG. 5, the electronic system 500 includes a host 110 and a display 320. The embodiment of the embodiment shown in FIG. 5 can refer to the related description of FIG. 3. The difference from the electronic system 300 is that the compression and decompression unit 111 is included in the host 110 of the electronic system 500. This compression and decompression unit 111 can perform the same compression operation as the compression and decompression unit 360. If the host 110 performs motion detection and determines that the original frame is a still frame, the host 110 performs the same compression operation as the compression and decompression unit 360 by using the compression and decompression unit 111 to test the compression ratio of the original frame. That is, the host 110 can pre-estimate whether the compression and decompression unit 360 can successfully compress this original frame to the buffer 350 before transmitting the current original frame to the display 320. Therefore, the controller 330 does not need to notify the host 110 of the compression result through the self-updating flag SRF shown in FIG.

After the compression rate test of the original frame is completed, the host 110 outputs a self-update enable signal SRE to the controller 330 according to the compression ratio. The controller 330 determines whether to operate in the "non-stationary frame mode" or the "still frame mode" based on the self-update enable signal SRE. If the compression rate of the original frame does not match the capacity of the buffer 350, even if the current original frame is a still frame, the host 110 maintains the self-renewal enable signal SRE in the disabled state and causes the controller 330 to operate in the non-stationary state. Frame mode", while host 110 continues to transmit The data D is displayed to transfer the original frame and subsequent original frames to the controller 330.

If the compression rate of the original frame conforms to the capacity of the buffer 350, the host 110 will transition the self-renewal enable signal SRE to the enabled state, and the host 110 stops transmitting the display data only after transmitting the original frame to the controller 330. D to the controller 330. The controller 330 enters the "still frame mode" in accordance with the self-update enable signal SRE. In the still frame mode, the controller 330 receives the original frame from the host 110 and then compresses the original frame to the buffer 350 via the compression and decompression unit 360. Next, the controller 330 no longer receives other original frames from the host 110, but decompresses the compressed frames in the buffer 350 through the compression and decompression unit 360 to obtain decompressed frames, and controls the display module 140 to display the slave frames. The decompressed frame obtained by the buffer 350 is switched to the "non-stationary frame mode" until the self-renewal enable signal SRE transitions to the disabled state.

Table 1 illustrates the operating current comparison table of Figs. 1, 2, and 3. Referring to FIG. 1 and Table 1, it is assumed that the current required to transmit the display data D by the host 110 shown in FIG. 1 is 300 mA, and the operating current of the controller 130 is 60 mA, and the total operating current of the host 110 and the controller 130 is 360 mA. .

Referring to FIG. 2 and Table 1, if the number of "still frames" in the original frame stream accounts for 80% of the total number of original frames, and the operation of the host 110 in FIG. 2 stops transmitting the display data D in the "still frame mode". The current is 80 mA, and the total operating current of the host 110 shown in FIG. 2 is 300 × (1-80%) + 80 × 80% = 124 mA. For the controller 230 shown in FIG. 2, if the operating current of the controller 230 and the frame buffer 250 in the "still frame mode" is 140 mA, the total operating current of the controller 230 is 60 × (1-80%) + 140 x 80% = 124 mA. Therefore, the total operating current of the host 110, the controller 230, and the frame buffer 250 shown in FIG. 2 is 248 mA.

Referring to FIG. 3 and Table 1, if the number of "still frames" in the original frame stream accounts for 80% of all the original frames, it can be successfully compressed into the "quiescent frame" of the buffer 350 in all "still frames". The number of all the "quiescent frames" is 80%, and the operating current of the host 110 shown in FIG. 2 stops transmitting the display data D in the "still frame mode" is 80 mA, and the total operating current of the host 110 shown in FIG. 3 is 300. × (1 - 80% × 80%) + 80 × 80% × 80% = 159.2 mA. For the controller 330 shown in FIG. 3, if the operating current of the controller 330, the compression and decompression unit 360, and the buffer 350 in the "still frame mode" is 90 mA, the total operating current of the controller 330 is 60×( 1-80% × 80%) + 90 × 80% × 80% = 79.2 mA. Therefore, the total operating current of the host 110, the controller 330, the buffer 350, and the compression and decompression unit 360 shown in FIG. 3 is 238.4 mA.

In summary, when the display 320 performs self-updating, the display data D can be stopped between the controller 330 and the host 110. Therefore, the electronic system 300 and the display 320 disclosed in the embodiment can reduce power consumption. Compared with the embodiment shown in FIG. 2, the capacity of the buffer 350 configured by the display 320 in the embodiment shown in FIG. 3 is smaller than that of the frame buffer 250 in FIG. 2, so that the cost can be reduced. As for the compression and decompression unit 360, although FIG. 3 depicts the compression and decompression unit 360 external to the controller 330 and the buffer 350, in other embodiments the compression and decompression unit 360 can be embedded in the controller. 330 or the interior of the buffer 350 to reduce costs. For example, the compression and decompression unit 360 is embedded in the controller 330. The compression and decompression unit 360 can be implemented in the controller 330 in a hardware, firmware or software manner.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the invention, and any one of ordinary skill in the art can make some modifications and refinements without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims.

100, 200, 300, 500‧‧‧ electronic systems

110‧‧‧Host

111, 360‧‧‧Compression and decompression unit

120, 220, 320‧‧‧ display

130, 230, 330‧‧‧ controller

140‧‧‧ display module

141‧‧ ‧ gate driver

142‧‧‧Source Driver

143‧‧‧ display panel

250‧‧‧ frame buffer

350‧‧‧buffer

361‧‧‧Compressor

362‧‧Decompressor

D‧‧‧Display information

S405~S470‧‧‧Steps

SRE‧‧‧ Self-renewal enable signal

SRF‧‧‧ Self-updating flag

1 is a functional block diagram illustrating a conventional display.

2 is a functional block diagram illustrating an embodiment of a display.

FIG. 3 is a block diagram showing the function of a display according to an embodiment of the invention.

4 is a schematic diagram showing the operation method of the electronic system of FIG. 3 according to an embodiment of the invention.

FIG. 5 is a block diagram showing the function of an electronic system according to another embodiment of the present invention.

110‧‧‧Host

140‧‧‧ display module

141‧‧ ‧ gate driver

142‧‧‧Source Driver

143‧‧‧ display panel

300‧‧‧Electronic system

320‧‧‧ display

330‧‧‧ Controller

350‧‧‧buffer

360‧‧‧Compression and decompression unit

361‧‧‧Compressor

362‧‧Decompressor

D‧‧‧Display information

SRE‧‧‧ Self-renewal enable signal

SRF‧‧‧ Self-updating flag

Claims (11)

A display controller for controlling a display module includes: a controller; a buffer; and a compression and decompression unit coupled between the buffer and the controller; wherein if the controller operates In a non-stationary frame mode, the controller receives an original image frame from a host external to the display controller, and the controller controls the display module to display the original image frame provided by the host, and the controller transmits the original image frame. An original image frame to the compression and decompression unit, the compression and decompression unit compressing the original image frame to obtain a compressed image frame, and the compression and decompression unit stores the compressed image frame to the buffer; and wherein The controller operates in a static frame mode, and the display device stops transmitting the display data to reduce power consumption, and the controller uses the compression and decompression unit to decode the compressed image frame stored in the buffer. Compressing to obtain a decompressed image frame, and the controller controlling the display module to display the decompressed image frame. The display controller of claim 1, wherein the compression and decompression unit comprises: a compressor coupled between the buffer and the controller, the compressor providing the controller The original image frame is compressed into the compressed image frame, and the compressed image frame is stored in the buffer; a decompressor coupled between the buffer and the controller, the decompressor decompressing the compressed image frame provided by the buffer into the decompressed image frame, and outputting the decompressed image frame To the controller. The display controller of claim 1, wherein the controller determines whether to operate in the non-stationary frame mode or the still frame mode according to a self-update enable signal of the host. The display controller of claim 1, wherein when the controller operates in the still frame mode, after the compression and decompression unit successfully compresses the original image frame to the buffer, the control The transmission of display data between the device and the host is stopped. The display controller of claim 1, wherein if the compression and decompression unit is unable to compress the original image frame to the buffer, the controller ends the still frame mode and switches to the non-stationary frame mode. To receive the next original image frame from the host. The display controller of claim 1, wherein the buffer has a capacity smaller than a data amount of the original image frame. A method for operating a display controller, comprising: receiving an original image frame from a host external to the display controller if the display controller is operating in a non-stationary frame mode; if the display controller is operating on the non-stationary frame In the mode, the original image frame is compressed to obtain a compressed image frame; if the display controller operates in the non-stationary frame mode, the compressed image frame is stored in a buffer; If the display controller is operated in the non-stationary frame mode, controlling a display module to display the original image frame provided by the host; if the display controller is operated in a still frame mode, decompressing is stored in the And compressing the image frame of the buffer to obtain a decompressed image frame; if the display controller is operated in the still frame mode, controlling the display module to display the decompressed image frame; and if the display controller is operated on the In the still frame mode, the display data between the controller and the host is stopped to reduce power consumption. The operating method of the display controller according to claim 7, wherein the display controller determines whether to operate in the non-stationary frame mode or the still frame mode according to a self-update enable signal of the host. The operating method of the display controller according to claim 7, further comprising: when the display controller is operated in the static frame mode, after the original image frame is successfully compressed to the buffer, the display controller Stop transmitting data between the host and the host. The operating method of the display controller according to claim 7, further comprising: if the display controller cannot compress the original image frame to the buffer, ending the still frame mode and switching to the non-stationary frame mode, The next original image frame is received from the host. A display comprising: a display module; a controller coupled to the display module, the controller receiving an original image frame from a host external to the display, wherein the controller controls the display mode if the controller operates in a non-stationary frame mode The group displays the original image frame provided by the host; a buffer; and a compression and decompression unit coupled between the buffer and the controller; wherein if the controller operates in the non-stationary frame mode, The controller transmits the original image frame to the compression and decompression unit, the compression and decompression unit compresses the original image frame to obtain a compressed image frame, and the compression and decompression unit stores the compressed image frame to the buffer And wherein if the controller is operating in a still-frame mode, stopping transmission of display data between the controller and the host to reduce power consumption, the controller storing the buffer in the buffer through the compression and decompression unit The compressed image frame is decompressed to obtain a decompressed image frame, and the controller controls the display module to display the decompressed image frame.