A method for arbitrating display output on a display device of a computer system comprises comparing a candidate display area with each rendering display area in a rendering collection and each waiting display area in a waiting collection, and determining whether at least one dependency exists for the candidate display area based on the comparing step, wherein the candidate display area is placed in the waiting queue when at least one dependency exists. The method further includes placing the candidate display area in the rendering collection when the at least one dependency does not exist. The method of arbitration includes releasing the current rendering display area. A method for scheduling display of data on a computer display device includes subdividing partitions of an output screen of the computer display device into display areas, determining whether at least one conflict exists between candidate display data, rendering display data in a rendering collection, and waiting display data in a waiting queue, and adding the candidate display data appropriately to either the rendering collection or the waiting queue based on at least one conflict existing.

A computer system and graphics controller which stores video data in memory corresponding to a plurality of video objects and presents the video objects on a video monitor, wherein a plurality of the video objects have differing numbers of bits per pixel formats. System memory stores video data in a plurality of memory areas for each of the plurality of video objects, wherein the plurality of video objects may have differing numbers of bits per pixel. The graphics controller obtains portions of the video data from the plurality of memory areas and in response provides video signals to the video monitor. The computer system and graphics controller performs pointer-based and/or display list-based video refresh operations that enable video object data to be assembled on a per window or per object basis, thereby greatly increasing the performance of the graphical display. The graphics controller maintains pointers to various areas or buffers in system memory comprising video or graphics display information. The graphics controller also manipulates respective object information workspace memory areas corresponding to each object or window, wherein the workspace areas specify data types, color depths or bits per pixel, 3D depth values, alpha blending information, screen position, etc. for the respective window or object on the screen. The graphics controller utilizes this information, as well as information received from the software driver regarding screen changes, to assemble a display refresh list in system memory. This information is used during the screen refresh to display the various windows or objects on the screen very quickly and efficiently. Thus only the number of bits per pixel required for each video object is required to be stored in memory.

A graphics controller (IMC) which performs pointer-based and/or display list-based video refresh operations that enable screen refresh data to be assembled on a per window basis, thereby greatly increasing the performance of the graphical display. The graphics controller maintains pointers to various buffers in system memory comprising video or graphics display information. The graphics controller manipulates respective object information workspace memory areas corresponding to each object or window, wherein the workspace areas specify data types, color depths, 3D depth values, alpha blending information, screen position, etc. for the respective window or object on the screen. Each workspace area also includes static and dynamic pointers which point to the location in system memory where the pixel data for the respective window or object is stored. The graphics controller utilizes this information, as well as information received from the software driver regarding screen changes, to assemble a display refresh list in system memory. This information is used during the screen refresh to display the various windows or objects on the screen very quickly and efficiently. Thus, the video display can be updated with new video data without requiring any system bus data transfers, which are required in prior art computer system architectures. The graphics controller dynamically adjusts the display refresh list for movement of objects and changes in relative depth priority which appear on the display. Thus the video data for the various windows and objects is stored in respective memory areas in the system memory, and pointers assembled in the display refresh list are used to reference this data during screen updates. Therefore, data is not required to be moved in or out of a frame buffer to reflect screen changes. Rather, in many instances, either the video data for a respective window or object is changed, or only the pointers in the display refresh list are manipulated, to affect a screen change.

An integrated memory controller (IMC) which incorporates novel memory, graphics, and audio processing capabilities in a single logical unit. The IMC includes numerous significant advances which provide greatly increased performance over prior art systems. The integrated memory controller (IMC) includes one or more symmetric memory ports for connecting to system memory. The IMC also includes video outputs, preferably RGB (red, green, blue) outputs as well as horizontal and vertical synchronization signal outputs, to directly drive the video display monitor. The IMC transfers data between the system bus and system memory and also transfers data between the system memory and the video display output, thereby eliminating the need for a separate graphics subsystem. The IMC also improves overall system performance and response using main system memory for graphical information and storage. The IMC system level architecture reduces data bandwidth requirements for graphical display data since the host CPU is not required to move data between main memory and the graphics subsystem as in conventional computers, but rather the graphical data resides in the same subsystem as the main memory. Therefore the host CPU or DMA master is not limited by the available bus bandwidth. The IMC includes compression and decompression engines for compressing and decompressing data within the system. The IMC also includes a novel pointer-based display list architecture which includes windows workspace areas spaces which define the format of the data and the data type to read or written.

The present invention discloses methods and apparatus for implementing automatic graphics operations with selectable triggering mechanism. One mechanism is hardware related, using the vertical counter in the video control section of the graphics processor. The other mechanism is software related, using the host to directly command the graphics processor. The graphics operations are specified in the header file written by the host in the frame buffer memory. Several header files can be chained together to form a sequence of header files corresponding to very complex graphics operations. Automatic graphics operations, therefore, can be completed without further host intervention resulting in powerful graphics, video, and animation performance.