Abstract: Systems, apparatuses, and methods for synchronizing backlight adjustments to frame updates in a display pipeline. A change in the ambient light is detected and as a result, backlight settings are adjusted. To offset a reduction in the backlight, the color intensity in the frames is increased. While the change in ambient light is detected asynchronously, the adjustment to the backlight settings and color intensity is synchronized to a frame update via a virtual channel for the auxiliary channel of the display interface.

Abstract: Methods and mechanisms for improved performance in a system with power management are described. A system includes a data storage device configured to store data and a display control unit configured to retrieve data from the data storage device. The data storage device may be placed in a reduced power state that results in increased latencies for accessing data within the device. The display control unit is configured to monitor an amount of data available for processing within the display control unit. In response to determining the amount of data has fallen to a threshold level, and in anticipation of a forthcoming data access request, the display control unit conveys an indication that prevents the data storage device from entering or remaining in the reduced power state. Subsequently, the display control unit conveys a request for data to the data storage device which will not be in the reduced power state.

Abstract: A method and device for data compression are presented, in which a data processor may receive a packet of image data which includes four groups of N bits, where N is an integer greater than 2. The data processor may compress the received packet of data, such that a total number of bits for the converted packet is less than four times N. The data processor may compress the received packet of image data by reducing the resolution of three of the values while maintaining the resolution of the fourth value. To reduce the resolution of the three values, the data processor may apply a dithering formula to the values. The data processor may then send the converted packet via an interface.

Abstract: Systems, apparatuses, and methods for generating a blur effect on a source image in a power-efficient manner. Pixels of the source image are averaged as they are read into pixel buffers, and then the source image is further downscaled by a first factor. Then, the downscaled source image is upscaled back to the original size, and then this processed image is composited with a semi-transparent image to create a blurred effect of the source image.

Abstract: A system and method for display frame compression and write to memory are disclosed. A display pipe is configured to generate frames for display. Additionally, the display pipe may be configured to initiate compression of a frame prior to detection of an idle condition. The display pipe may also be configured to determine to selectively allow write-back logic to operate responsive to detecting various conditions. The display pipe may compress a frame and compare the size of the frame as compressed to a threshold value. If the size of the compressed frame exceeds the threshold value, write back of the compressed frame to memory is prevented. Write back of the compressed frame may be further conditioned on the detection of other conditions.

Abstract: Systems, apparatuses, and methods for preventing charge accumulation on a display panel of a display. A display pipeline is configured to drive a display using a variable frame refresh rate. The display may also be driven by a polarity inversion cadence to alternate the polarity on the display panel on back-to-back frames. In some cases, the frame refresh rate cadence, as specified in frame packets which contain configuration data for processing corresponding frames, can cause a charge accumulation on the display panel if an odd number of frames are displayed at a first frame refresh rate before switching to a second frame refresh rate. Accordingly, in these cases, the display pipeline may override the frame refresh rate setting for a given frame to cause an even number of frames to be displayed at the first frame refresh rate.

Abstract: Systems, apparatuses, and methods for performing linear scaling in a display control unit. A display control unit receives source image data that has already been gamma encoded with an unknown gamma value. The display control unit includes a hard-coded LUT storing a gamma curve of a first gamma value which is used to perform a degamma operation on the received source image data. Even if the first gamma value used to perform the degamma operation is different from the gamma value used to gamma encode the source image data, fewer visual artifacts are generated as compared with not performing a degamma operation. After the degamma operation is performed, the source image data may be linearly scaled.

Abstract: In an embodiment, a system includes a display processing unit configured to process a video sequence for a target display. In some embodiments, the display processing unit is configured to composite the frames from frames of the video sequence and one or more other image sources. The display processing unit may be configured to write the processed/composited frames to memory, and may also be configured to generate statistics over the frame data, where the generated statistics are usable to encode the frame in a video encoder. The display processing unit may be configured to write the generated statistics to memory, and the video encoder may be configured to read the statistics and the frames. The video encoder may be configured to encode the frame responsive to the statistics.

Abstract: Systems and methods for determining priorities of pixel fetch requests of separate requestors in a display control unit. The distance between the oldest pixel in an output buffer and the output equivalent coordinate of the oldest outstanding source pixel read request for each requestor in the display control unit is calculated. Then, a priority is assigned to each requestor based on this calculated distance. If a given requestor lags behind the other requestors based on a comparison of the distance between the oldest pixel and the output equivalent coordinate of the oldest outstanding source pixel read, then source pixel fetch requests for this given requestor are given a higher priority than source pixel fetch requests for the other requestors.

Abstract: Systems, apparatuses, and methods for driving a split display with multiple display pipelines. Frames for driving a display are logically divided into portions, a first display pipeline drives a first portion of the display, and a second display pipeline drives a second portion of the display. To ensure synchronization between the two display pipelines, a repeat vertical blanking interval (VBI) signal is generated if either of the display pipelines has not already received the frame packet with configuration data for the next frame. When the repeat VBI signal is generated, both display pipelines will repeat processing of the current frame.

Abstract: Systems, apparatuses, and methods for generating a blur effect on a source image in a power-efficient manner. Pixels of the source image are averaged as they are read into pixel buffers, and then the source image is further downscaled by a first factor. Then, the downscaled source image is upscaled back to the original size, and then this processed image is composited with a semi-transparent image to create a blurred effect of the source image.

Abstract: Systems, apparatuses, and methods for passing source pixel data through a display control unit. A display control unit includes N-bit pixel component processing lanes for processing source pixel data. When the display control unit receives M-bit source pixel components, wherein ‘M’ is greater than ‘N’, the display control unit may assign the M-bit source pixel components to the N-bit processing lanes. Then, the M-bit source pixel components may passthrough the pixel component processing elements of the display control unit without being modified.

Abstract: A display pipe is configured to generate output frames for display. Additionally, the display pipe may be configured to compress an output frame and write the compressed frame back to memory responsive to detecting static content in successive output frames. The display pipe may also be configured to determine to selectively allow write-back logic to operate when doing so will not cause a pixel underrun to the display. If an underrun might occur, write-back logic is temporarily disabled. If write-back is successful, the display pipe may read the compressed frame from memory for display instead of reading the source frames for compositing and display.

Abstract: An apparatus for processing graphics data may include a plurality of processing pipelines, each pipeline configured to receive and process pixel data. A functional unit may combine the outputs of each processing pipeline. A buffer included in a given processing pipeline may be configured to store data from the functional unit in response to a determination that the given processing pipeline is inactive. The buffer may then send the stored data to a memory.

Abstract: Systems, apparatuses, and methods for preventing charge accumulation on a display panel of a display. A display pipeline is configured to drive a display using a variable frame refresh rate. The display may also be driven by a polarity inversion cadence to alternate the polarity on the display panel on back-to-back frames. In some cases, the frame refresh rate cadence, as specified in frame packets which contain configuration data for processing corresponding frames, can cause a charge accumulation on the display panel if an odd number of frames are displayed at a first frame refresh rate before switching to a second frame refresh rate. Accordingly, in these cases, the display pipeline may override the frame refresh rate setting for a given frame to cause an even number of frames to be displayed at the first frame refresh rate.

Abstract: A graphics system may include a display pipe with a buffer configured to store pixels to be processed by a display controller for displaying on a display device, with a buffer control circuit coupled to the buffer to supply pixels to the display controller. When the buffer control circuit detects an underrun of the buffer responsive to the display controller attempting to read pixels from the buffer that have not yet been written to the buffer, the buffer control circuit may supply an underrun pixel to the display. The underrun pixel may be selected from a set of previously stored set of underrun pixels, which may include a most recent valid pixel read by the display controller. A read pointer representative of the location in the buffer from where the display controller is currently attempting to read may be advanced even when an underrun condition occurs.

Abstract: An apparatus for processing graphics data may include a plurality of processing pipelines, each pipeline configured to receive and process pixel data. A functional unit may combine the outputs of each processing pipeline. A buffer included in a given processing pipeline may be configured to store data from the functional unit in response to a determination that the given processing pipeline is inactive. The buffer may then send the stored data to a memory.

Abstract: Systems, apparatuses, and methods for synchronizing backlight adjustments to frame updates in a display pipeline. A change in the ambient light is detected and as a result, backlight settings are adjusted. To offset a reduction in the backlight, the color intensity in the frames is increased. While the change in ambient light is detected asynchronously, the adjustment to the backlight settings and color intensity is synchronized to a frame update via a virtual channel for the auxiliary channel of the display interface.

Abstract: A graphics system may include one or more processing units for processing a current display frame, each processing unit including a plurality of parameter registers for storing parameter settings used in processing the current display frame. A parameter buffer in the graphics system may store frame packets, with each frame packet containing information corresponding to parameter settings to be used for at least one display frame. A control circuit coupled to the buffer and to the one or more processing units may retrieve and process a top frame packet from the parameter buffer to update one or more of the parameter registers according to the contents of the top frame packet. The control circuit may issue DMA requests to fill the parameter buffer with frame packets transferred from system memory, where the frame packets may be written by an application (or software) executing on a central processing unit.

Abstract: Systems, apparatuses, and methods for driving a split display with multiple display pipelines. Frames for driving a display are logically divided into portions, a first display pipeline drives a first portion of the display, and a second display pipeline drives a second portion of the display. To ensure synchronization between the two display pipelines, a repeat vertical blanking interval (VBI) signal is generated if either of the display pipelines has not already received the frame packet with configuration data for the next frame. When the repeat VBI signal is generated, both display pipelines will repeat processing of the current frame.