Information routing for transfer buffers

A bridge circuit for connecting a primary bus to a plurality of secondary busses, said bridge circuit comprising:

• a primary node, said primary node being arranged for connection to said primary bus;
• a first number of secondary nodes, said secondary nodes being arranged for connection to a corresponding first number of secondary busses;
• and
• bridge control means connecting said primary node to said first number of secondary nodes, said bridge control means including routing control circuitry, said routing control circuitry being selectively operable for routing information related to data transfer transactions between said primary node and said secondary nodes, said routing control circuitry being further selectively operable for routing said information between selected ones of said secondary nodes, said bridge control means further including buffer means, said buffer means including a second number of buffer groups, each of said buffer groups including at least two buffer devices, each of said buffer devices being arranged for temporarily storing information related to said data transfer transactions passing through said bridge circuit wherein said transactions include request information passing through said bridge circuit in a first direction and completion information passing through said bridge circuit in a direction opposite said first direction, said request information for any of said transactions being temporarily stored in a designated one of said buffer devices, said completion information also being stored in said designated one of said buffer devices during a completion phase of said transaction.

A method for processing an information transfer transaction, said transaction including an information transfer request and an information transfer completion, said information transfer transaction being routed through a bridge circuit, said bridge circuit including a plurality of buffer devices for storing said information transfer request and said information transfer completion, said method comprising:

• temporarily storing request related information in a designated buffer device when an information transfer request is being routed through said bridge circuit;
• naming said designated buffer to indicate said designated buffer contains request related information;
• replacing said request related information in said designated buffer with completion related information during a completion phase of said information transfer;
• and
• renaming said designated buffer to indicate said designated buffer contains completion related information during said completion phase of said information transfer transaction.

An information processing system comprising:

• a primary bus;
• a memory means coupled to said primary bus;
• at least one processor device coupled to said primary bus;
• a first number of secondary busses;
• and
• a bridge circuit connecting said primary bus to said secondary busses, said bridge circuit including a primary node arranged for connection to said primary bus, said bridge circuit further including a first number of secondary nodes, said secondary nodes being arranged for connection to a corresponding one of said first number of secondary busses, said bridge circuit further including bridge control means connecting said primary node to said first number of secondary nodes, said bridge control means including routing control circuitry, said routing control circuitry being selectively operable for routing information related to data transfer transactions between said primary node and said secondary nodes, said routing control circuitry being further selectively operable for routing said information between selected ones of said secondary nodes, said bridge control means further including buffer means, said buffer means including a second number of buffer groups, each of said buffer groups including at least two buffer devices, each of said buffer devices being arranged for temporarily storing information related to said data transfer transactions passing through said bridge circuit wherein each of said second number of buffer groups is connected to a different one of said primary and secondary nodes, said bridge circuit further including a primary master function connected between said primary node and a primary master bus within said routing control circuitry, and a primary target function connected between said primary node and one of said second number of buffer groups.

A bridge circuit for connecting a primary bus to a plurality of secondary busses, said bridge circuit comprising:

• a primary node, said primary node being arranged for connection to said primary bus;
• a first number of secondary nodes, said secondary nodes being arranged for connection to a corresponding first number of secondary busses;
• and
• bridge control means connecting said primary node to said first number of secondary nodes, said bridge control means including routing control circuitry, said routing control circuitry being selectively operable for routing information related to data transfer transactions between said primary node and said secondary nodes, said routing control circuitry being further selectively operable for routing said information between selected ones of said secondary nodes, said bridge control means further including buffer means, said buffer means including a second number of buffer groups, each of said buffer groups including at least two buffer devices, each of said buffer devices being arranged for temporarily storing information related to said data transfer transactions passing through said bridge circuit wherein said transactions include request information passing through said bridge circuit in a first direction and completion information passing through said bridge circuit in a direction opposite said first direction, said request information for any of said transactions being temporarily stored in a designated one of said buffer devices, said completion information also being stored in said designated one of said buffer devices during a completion phase of said transaction.