Display processor for a wireless device

• US 7,868,890 B2
• Filed: 09/29/2004
• Issued: 01/11/2011
• Est. Priority Date: 02/24/2004
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Ludwin, Albert Scott, King, Scott Howard
• Primary Examiner(s): Washburn; Daniel
• Application Number:
  US10/954,408
• Publication Number:
  US 20050184993A1
• Time in Patent Office: 2,295 Days
• Field of Search: 345/502, 345/503, 345/519, 345/520
• US Class Current: 345/502
• CPC Class Codes: G09G 2340/0407 Resolution change, inclusive of the use of different resolutions for different screen areas
• CPC Class Codes: G09G 2340/0492 Change of orientation of the displayed image, e.g. upside-down, mirrored
• CPC Class Codes: G09G 2340/10 Mixing of images, i.e. displayed pixel being the result of an operation, e.g. adding, on the corresponding input pixels
• CPC Class Codes: G09G 2340/125 wherein one of the images is motion video
• CPC Class Codes: G09G 3/3611 Control of matrices with row and column drivers
• CPC Class Codes: G09G 5/006 Details of the interface to the display terminal specific for a display terminal using a CRT G09G1/167; using a flat panel G09G3/2096; circuits for interfacing with colour displays G09G5/04
• CPC Class Codes: G09G 5/02 characterised by the way in which colour is displayed details of colour display specific for CRTs G09G1/28; specific for flat matrix panels other than liquid crystal displays G09G3/2003; specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 5/363 Graphics controllers
• CPC Class Codes: G09G 5/39 Control of the bit-mapped memory
• CPC Class Codes: G09G 5/393 Arrangements for updating the contents of the bit-mapped memory
• CPC Class Codes: G09G 5/397 Arrangements specially adapted for transferring the contents of two or more bit-mapped memories to the screen simultaneously, e.g. for mixing or overlay G09G5/02 takes precedence
• CPC Class Codes: H04M 1/72427 for supporting games or graphical animations
• CPC Class Codes: H04W 52/027 by controlling a display operation or backlight unit
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A display processor includes an interface unit, an instruction processor, a synchronization unit, at least one processing unit, and a device buffer. The interface unit receives input image data (e.g., from a main memory) and provides output image data for a frame buffer. The instruction processor receives instructions (e.g., in a script or list) and directs the operation of the processing unit(s). The synchronization unit determines the location of a read pointer for the frame buffer and controls the writing of output image data to the frame buffer to avoid causing visual artifacts on an LCD screen. The processing unit(s) may perform various post-processing functions such as region flip, region rotation, color conversion between two video formats (e.g., from YCrCb to RGB), up/down image size rescaling, alpha-blending, transparency, text overlay, and so on.

Claims

1. An integrated circuit for a wireless device, the integrated circuit comprising:

a display processor;

a first external bus interface unit that couples the display processor to a first bus that is external to the display processor, wherein the first external bus interface is configured to receive input image data and provide the input image data to the display processor;

one or more additional processors;

a second external bus interface unit that is configured to provide output image data for presentation on an electronic screen; and

a synchronization unit configured to track a write pointer and a read pointer for a frame buffer associated with the electronic screen and ensure that the write pointer lags the read pointer,

wherein the display processor includes at least one processing unit configured to perform at least one post-processing function on the input image data to obtain the output image data and a device buffer configured to store the output image data, wherein the device buffer acts like a virtual buffer and stores one or more rows of data blocks that comprise less than one complete frame of the output image data for the electronic screen,

wherein the device buffer is updated at different update rates for different regions associated with the electronic screen, wherein a refresh rate of the electronic screen is greater than one or more of the update rates to the frame buffer associated with the electronic screen for the different regions, wherein the different regions are associated with different data sources, and wherein the different regions include a video graphics region that displays video graphics and at least one status region that indicates a status of the wireless device, and

wherein the display processor is configured to provide the output image data in a line by line format from the device buffer to the frame buffer associated with the electronic screen, which is used to store a frame of the output image data for presentation on the electronic screen, wherein one or more of the data blocks stored in the device buffer are stored in non-contiguous locations within the device buffer, and wherein lines associated with one of the rows of data blocks are retrieved from the device buffer and written to the frame buffer using the second external bus interface while new data blocks for another row arrive via the first external bus interface.

2. The integrated circuit of claim 1, wherein the at least one processing unit is configured to process the input image data in blocks, and wherein the second external bus interface unit is configured to provide the output image data in lines.

3. The integrated circuit of claim 1, wherein the at least one processing unit is configured to perform region flip, region rotation, color conversion, image size rescaling, alpha-blending, transparency, text overlay, or a combination thereof.

4. The integrated circuit of claim 1, further comprising:

an instruction processor configured to receive instructions in a list, execute the instructions in the list until a termination condition is encountered, and direct the at least one processing unit to process the input image data in accordance with the instructions.

5. The integrated circuit of claim 1, wherein the synchronization unit is configured to receive a vertical synchronization signal indicating each refresh cycle for the electronic screen and to determine timing for providing the output image data from the second external bus interface unit to avoid causing visual artifacts on the electronic screen.

6. An apparatus comprising:

means for receiving input image data for an electronic screen;

means for performing at least one post-processing function on the input image data to obtain output image data, wherein the means for performing at least one post-processing function comprises a processing unit and a device buffer configured to store the output image data, wherein the device buffer acts like a virtual buffer and stores one or more rows of data blocks that comprise less than one complete frame of the output image data for the electronic screen;

means for providing the output image data in line by line format to a frame buffer associated with the electronic screen, wherein the frame buffer is used to store a frame of the output image data for presentation on the electronic screen, wherein one or more of the data blocks stored in the device buffer are stored in non-contiguous locations within the device buffer, and wherein lines associated with one of the rows of data blocks are retrieved from the device buffer and written to the frame buffer via an external bus interface while new data blocks for another row are retrieved via another external bus interface;

means for tracking a write pointer and a read pointer for the frame buffer associated with the electronic screen, wherein the means for tracking ensures that the write pointer lags the read pointer; and

means for updating the device buffer at different update rates for different regions associated with the electronic screen, wherein a refresh rate of the electronic screen is greater than one or more of the update rates to the frame buffer associated with the electronic screen for the different regions, wherein the different regions are associated with different data sources, and wherein the different regions include a video graphics region that displays video graphics and at least one status region that indicates a status of the apparatus.

7. The apparatus of claim 6, wherein the at least one post-processing function comprises region flip, region rotation, color conversion, image size resealing, alpha-blending, transparency, text overlay, or a combination thereof.

8. The apparatus of claim 6, further comprising:

means for receiving a vertical synchronization signal indicating each refresh cycle for the electronic screen; and

means for determining timing for providing the output image data, based on the vertical synchronization signal, to avoid causing visual artifacts on the electronic screen.

9. A wireless device comprising:

a display processor;

a first bus;

a first external bus interface unit that couples the display processor to the first bus that is external to the display processor, wherein the first external bus interface is configured to receive input image data via the first bus and provide the input image data to the display processor;

one or more additional processors;

a second bus;

a second external bus interface unit configured to provide output image data from the display processor via the second bus in a line by line format to a frame buffer of an electronic screen unit, wherein the frame buffer is used to store a frame of the output image data for presentation on an electronic screen; and

a synchronization unit configured to track a write pointer and a read pointer for the frame buffer associated with the electronic screen and ensure that the write pointer lags the read pointer,

wherein the display processor includes at least one processing unit configured to perform at least one post-processing function on the input image data to obtain the output image data, and a device buffer configured to store the output image data, wherein the device buffer acts like a virtual buffer and stores one or more rows of data blocks that comprise less than one complete frame of the output image data for the electronic screen,

wherein the device buffer is updated at different update rates for different regions associated with the electronic screen, wherein a refresh rate of the electronic screen is greater than one or more of the update rates to the frame buffer associated with the electronic screen for the different regions, wherein the different regions are associated with different data sources, and wherein the different regions include a video graphics region that displays video graphics and at least one status region that indicates a status of the wireless device, and

wherein one or more of the data blocks stored in the device buffer are stored in non-contiguous locations within the device buffer, and wherein lines associated with one of the rows of data blocks are retrieved from the device buffer and written to the frame buffer using the second external bus interface while new data blocks for another row arrive via the first external bus interface.

10. The wireless device of claim 9, wherein the display processor includes at least one of:

a flip processor that provides flipping the input image left-to-right, up-and-down, or both left-to-right and up-and-down;

a rotate processor that rotates the input image in 90 degree increments;

a color, convert, and scale processor that upsamples for red and blue chrominance components of the input image data; and

a mix, blend, and crop processor that alpha-blends the input image data.

11. A method comprising:

receiving input image data for an electronic screen;

performing at least one post-processing function on the input image data to obtain output image data, wherein the performing at least one post-processing function comprises a processing unit and a device buffer configured to store the output image data, wherein the device buffer acts like a virtual buffer and stores one or more rows of data blocks that comprise less than one complete frame of the output image data for the electronic screen;

providing the output image data in line by line format to a frame buffer associated with the electronic screen, wherein the frame buffer is used to store a frame of the output image data for presentation on the electronic screen, wherein one or more of the data blocks stored in the device buffer are stored in non-contiguous locations within the device buffer, and wherein lines associated with one of the rows of data blocks are retrieved from the device buffer and written to the frame buffer via an external bus interface while new data blocks for another row are retrieved via another external bus interface;

tracking a write pointer and a read pointer for the frame buffer associated with the electronic screen, wherein the tracking ensures that the write pointer lags the read pointer; and

updating the device buffer at different update rates for different regions associated with the electronic screen, wherein a refresh rate of the electronic screen is greater than one or more of the update rates to the frame buffer associated with the electronic screen for the different regions, wherein the different regions are associated with different data sources, and wherein the different regions include a video graphics region that displays video graphics and at least one status region that indicates a status of an apparatus.

12. The method of claim 11, wherein the at least one post-processing function comprises region flip, region rotation, color conversion, image size resealing, alpha-blending, transparency, text overlay, or a combination thereof.

13. The method of claim 11, further comprising:

receiving a vertical synchronization signal indicating each refresh cycle for the electronic screen; and

determining timing for providing the output image data, based on the vertical synchronization signal, to avoid causing visual artifacts on the electronic screen.