Apparatus, method and system for accelerated graphics port bus bridges

A method of transferring data within a computer system, said computer system having a central processing unit, a core logic connected to said central processing unit, system random access memory connected to said core logic, and a first AGP bus connected to said core logic, said computer system further having an AGP to AGP bridge, said AGP to AGP bridge constructed and arranged to connect at least two AGP-compatible devices to said computer system via said first AGP bus, said AGP to AGP bridge further having a first interface target and arbiter connected to said first AGP bus, a first read data return queue connected to said first interface target and arbiter, a first read and write request queue connected to said first interface target and arbiter, a first write data queue connected to said first interface target and arbiter, a second interface target and arbiter connected to a second AGP bus, a second read data return queue connected to said second interface target and arbiter, said second read data return queue further connected to said first read data return queue, a second read and write request queue connected to said second interface target and arbiter, said second read and write request queue further connected to said first read and write request queue, a second write data queue connected to said second interface target and arbiter, said second write data queue further connected to said first write data queue, a third interface target and arbiter connected to a third AGP bus, a third read data return queue connected to said third interface target and arbiter, said third read data return queue further connected to said first read data return queue, a third read and write request queue connected to said third interface target and arbiter, said third read and write request queue further connected to said first read and write request queue, a third write data queue connected to said third interface target and arbiter, said third write data queue further connected to said first write data queue, and a flow control logic, said flow control logic connected to said first read data return queue, said first read and write request queue, said first write data queue, said first interface target and arbiter, said second read data return queue, said second read and write request queue, said second write data queue, said second interface target and arbiter, said third read data return queue, said third read and write request queue, said third write data queue, and said third interface target and arbiter, said method comprising the steps of:

• (a) transferring data between said first AGP bus and said second AGP bus.

A method of transferring data within a computer system, said computer system having a central processing unit, a core logic connected to said central processing unit, system random access memory connected to said core logic, and a first AGP bus connected to said core logic, said computer system further having an AGP to AGP bridge, said AGP to AGP bridge constructed and arranged to connect at least two AGP-compatible devices to said computer term via said first AGP bus, said AGP to AGP bridge further having a first interface target and arbiter connected to said first AGP bus, a first read data return queue connected to said first interface target and arbiter, a first read and write request queue connected to said first interface target and arbiter, a first write data queue connected to said first interface target and arbiter, a second interface target and arbiter connected to a second AGP bus, a second read data return queue connected to said second interface target and arbiter, said second read data return queue further connected to said first read data return queue, a second read and write request queue connected to said second interface target and arbiter, said second read and write request queue further connected to said first read and write request queue, a second write data queue connected to said second interface target and arbiter, said second write data queue further connected to said first write data queue, a third interface target and arbiter connected to a third AGP bus, a third read data return queue connected to said third interface target and arbiter, said third read data return queue further connected to said first read data return queue, a third read and write request queue connected to said third interface target and arbiter, said third read and write request queue further connected to said first read and write request queue, a third write data queue connected to said third interface target and arbiter, said third write data queue further connected to said first write data queue, and a flow control logic, said flow control logic connected to said first read data return queue, said first read and write request queue, said first write data queue, said first interface target and arbiter, said second read data return queue, said second read and write request queue, said second write data queue, said second interface target and arbiter, said third read data return queue, said third read and write request queue, said third write data queue, and said third interface target and arbiter, said method comprising the steps of:

• (a) transferring data between said first AGP bus and said third AGP bus.

A computer system, comprising:

• a central processing unit;
• a core logic connected to said central processing unit;
• a system random access memory connected to said core logic;
• a first AGP bus connected to said core logic, wherein said first ASP bus comprises a 32-bit bus or a 64-bit bus;
• an AGP to AGP bridge connecting at least two AGP-compatible devices to said computer system via said first AGP bus, wherein said AGP to AGP bridge comprises:
• a first interface target and arbiter connected to said first AGP bus;
• a first read data return queue connected to said first interface target and arbiter;
• a first read and write request queue connected to said first interface target and arbiter;
• a first write data queue connected to said first interface target and arbiter;
• a second interface target and arbiter connected to a second AGP bus;
• a second read data return queue connected to said second interface target and arbiter, said second read data return queue further connected to said first mad data return queue;
• a second read and write request queue connected to said second interface target and arbiter, said second read and write request queue further connected to said first read and write request queue;
• a second write data queue connected to said second interface target and arbiter, said second write data queue further connected to said first write data queue;
• a third interface target and arbiter connected to a third AGP bus;
• a third read data return queue connected to said third interface target and arbiter, said third read data return queue further connected to said first read data return queue;
• a third read and write request queue connected to said third interface target and arbiter, said third read and write request queue further connected to said first read and write request queue;
• a third write data queue connected to said third interface target and arbiter, said third write data queue further connected to further connected to said first write data queue;
• a PCI interface;
• and
• a flow control logic, said flow control logic connected to said first read data return queue, said first read and write request queue, said first write data queue, said first interface target and arbiter, said second read data return queue, said second read and write request queue, said second write data queue, said second interface target and arbiter, said third read data return queue, said third mad and write request queue, said third write data queue, and said third interface target and arbiter;
• wherein said flow control logic regulates the transfer of requests, replies, and data between said first AGP bus, said second AGP bus and said third AGP bus.

A computer system, comprising:

• a central processing unit;
• a core logic connected to said central processing unit;
• a system random access memory connected to said core logic;
• and
• a first AGP bus connected to said core logic;
• and
• means for bridging at least two AGP-compatible devices to said computer system via said first AGP bus, wherein said bridging means comprises:
• a first interface target and arbiter connected to said first AGP bus;
• a first read data return queue connected to said first interface target and arbiter;
• a first read and write request queue connected to said first interface target and arbiter;
• a first write data queue connected to said first interface target and arbiter;
• a second interface target and arbiter connected to a second AGP bus;
• a second read data return queue connected to said second interface target and arbiter, said second read data return queue further connected to said first read date return queue;
• a second read and write request queue connected to said second interface target and arbiter, said second read and write request queue further connected to said first read and write request queue;
• a second write data queue connected to said second interface target and arbiter, said second write date queue further connected to said first write data queue;
• a third interface target and arbiter connected to a third AGP bus;
• a third read data return queue further connected to said third interface target and arbiter, said third read data return queue further connected to said first read data return queue;
• a third read and write request queue connected to said third interface target and arbiter, said third read and write request queue further connected to said first read and write request queue;
• a third write data queue connected to said third interface target and arbiter, said third write data queue further connected to further connected to said first write data queue;
• and
• a flow control logic, said flow control logic connected to said first read data return queue, said first read and write request queue, said first write data queue, said first Interface target and arbiter, said second read data return queue, said second read and write request queue, said second write data queue, said second interface target an arbiter, said third read data return queue, said third read and write request queue, said third write data queue, and said third interface target and arbiter;
• wherein said flow control logic regulates the transfer of requests, replies and data between said first AGP bus, said second AGP bus and said third AGP bus.

A computer system, comprising:

• a central processing unit;
• a core logic connected to said central processing unit;
• a system random access memory connected to said core logic;
• and
• a first AGP bus connected to said core logic;
• and
• means for bridging at least two AGP-compatible devices to said computer system via said first AGP bus, wherein said bridging means comprises a PCI interface, said PCI interface comprising:
• a first PCI master/target interface connected to said first AGP bus;
• a first PCI target state machine connected to said first PCI master/target interface;
• a first PCI master state machine connected to said first PCI master/target interface;
• a second PCI master/target arbiter connected to said second AGP bus;
• a second PCI target state machine connected to said second PCI master/target arbiter and to said first PCI target state machine;
• a second PCI master state machine connected to said second PCI master/target arbiter and to said first PCI master state machine;
• a third PCI master/target arbiter connected to said third AGP bus;
• a third PCI target state machine connected to said third PCI master/target arbiter and to said first PCI target state machine;
• and
• a third PCI master state machine connected to said third PCI master/target arbiter and to said first PCI master state machine;
• wherein said PCI interface handles request, reply, and data transfers between said first AGP bus, said second AGP bus and said third AGP bus within the PCI protocol.

An AGP to AGP bridge comprising:

• a first interface target and arbiter connected to said first AGP bus;
• a first read data return queue connected to said first interface target and arbiter;
• a first read and write request queue connected to said first interface target and arbiter;
• a first write data queue connected to said first interface target and arbiter;
• a second interface target and arbiter connected to a second AGP bus;
• a second read data return queue connected to said second interface target and arbiter, said second read data return queue further connected to said first read data return queue;
• a second read and write request queue connected to said second interface target and arbiter, said second read and write request queue further connected to said first read and write request queue;
• a second write data queue connected to said second interface target and arbiter, said second write data queue further connected to said first write data queue;
• a third interface target and arbiter connected to a third AGP bus;
• a third read data return queue connected to said third interface target and arbiter, said third read data return queue further connected to said first read data return queue;
• a third read and write request queue connected to said third interface target and arbiter, said third read and write request queue further connected to said first read and write request queue;
• a third write data queue connected to said third interface target and arbiter, said third write data queue further connected to further connected to said first write data queue;
• and
• a flow control logic, said flow control logic connected to said first read data return queue, said first read and write request queue, said first write data queue, said first interface target and arbiter, said second read data return queue, said second read and write request queue, said second write data queue, said second interface target and arbiter, said third read data return queue, said third read and write request queue, said third write data queue, and said third interface target and arbiter;
• wherein said flow control logic regulates the transfer of requests, replies, and data between said first AGP bus, said second AGP bus and said third AGP bus.