Patent ID: 6728822
Filing Date: 2004-04-27
Classification: G06F

Abstract:
A bus bridge circuit for use in performing in situ inspections of PCI transactions in a notebook personal computer information processing system having a primary PCI bus that is not directly accessible to a user, at least one peripheral device connected to the said primary PCI bus, and a secondary bus that is directly accessible to a user, comprising:a control input means for switching operation modes of said bus bridge circuit, which is connected between said primary PCI bus and said secondary bus of the notebook personal computer and for selectively generating a passthrough mode signal; and a bypass path comprising a passthrough logic circuit connected in parallel with said bus bridge circuit provided between an input side and an output side of said bus bridge circuit; whereby when said passthrough mode signal from said control input means exhibits a first state, said bus bridge circuit is enabled for operation and said bypass path is disabled for operation, thereby causing said bus bridge circuit to be operated in its normal mode; and when the passthrough mode signal from said control input means exhibits a second state, said bus bridge circuit is disabled for operation and said bypass path is enabled for operation, thereby causing predetermined bus signals of a plurality of bus signals on said primary bus to be output on said secondary bus; whereby in situ inspections of PCI bus transactions are performed during said passthrough mode.