Response reordering mechanism

An integrated circuit chip comprising:

• a transmit circuit adapted to receive non-posted read requests from at least one requestor and transmit upstream commands based on said non-posted read requests, each of said upstream commands being uniquely identified by a command tag;
• a receive circuit adapted to receive response data in reply to commands previously transmitted by said transmit circuit, and transmit responses to said at least one requestor based on said response data;
• and
• a response reordering mechanism adapted to control said receive circuit to transmit said responses in correct order, said response reordering mechanism comprising a buffer unit for storing received response data, said buffer unit having a plurality of buffer elements each being uniquely assigned to one of said command tags.

A computer system comprising:

• at least one peripheral component;
• and
• a southbridge comprising a transmit engine adapted to receive non-posted read requests from at least one peripheral component controller and transmit upstream commands based on said non-posted read requests, each of said upstream commands being uniquely identified by a command tag;
• and a receive engine adapted to receive response data in reply to commands previously transmitted by said transmit engine, and transmit responses to said at least one peripheral component controller based on said response data;
• wherein said southbridge further comprises a response reordering mechanism adapted to control said receive engine to transmit said responses in correct order, said response reordering mechanism comprising a buffer unit for storing received response data, said buffer unit having a plurality of buffer elements each being uniquely assigned to one of said command tags.

A method of operating a southbridge device, the method comprising:

• receiving non-posted read requests from at least one requestor;
• transmitting upstream commands based on said non-posted read requests, each of said upstream commands being uniquely identified by a command tag;
• receiving response data in reply to previously transmitted commands;
• and
• transmitting responses to said at least one requestor based on said response data;
• wherein transmitting said responses comprises:
• reordering said received response data by accessing a buffer of said southbridge device, said buffer storing said received response data and having a plurality of buffer elements each being uniquely assigned to one of said command tags.