System and method for graphics data concurrency and coherency

A graphics controller for coordinating access to graphics resources by multiple pipelines executing on a host processor that is coupled to the graphics controller, the graphics controller comprising:

• a BLTBIT engine for transferring data between memory locations according to commands provided by an operating system and an application;
• first and second operating registers coupled to the BLTBIT engine, for receiving commands from the operating system and application, respectively;
• arbitration logic coupled to the first and second operating registers for granting access to the BLTBIT engine according to access signals provided by the application and operating system;
• and
• first and second sets of request/grant bits associated with the first and second operating registers, respectively, and coupled to the arbitration logic for registering access signals generated by the application and operating system, respectively and by the arbitration logic.

A graphics controller for processing graphics commands from an application program and an operating system running on a host processor that is coupled to the graphics controller, the graphics controller comprising:

• a command parser for interpreting commands from the application program;
• a BLTBIT engine;
• a first operating register for receiving commands from the operating system and operating the BLTBIT engine according to the received commands;
• a second operating register for receiving selected commands from the command parser and operating the BLTBIT engine according to the selected commands;
• signaling bits associated with the first and second operating registers;
• and arbitration logic coupled to the signaling bits and to the first and second operating registers, for coupling commands from the first or second operating register to the BLTBIT engine according to an arbitration scheme.

A method for concurrently processing commands from an operating system and an application program in a graphics controller having a command parser for routing commands to graphics resources, including a BLTBIT engine, the method comprising the steps of:

• receiving commands from the operating system in a first register associated with the BLTBIT engine;
• setting a request bit when the command received in the first register is a BLTBIT command;
• receiving a command from the application program in a first buffer associated with the command parser;
• setting a request bit when the command parser detects a BLTBIT command in the first buffer;
• gating the commands in the first register and first buffer to the BLTBIT engine according to an arbitration scheme.