Abstract: A method and apparatus for facilitating direct access to a serial Advanced Technology Attachment (ATA) device by an autonomous subsystem in the absence of the main operating system (OS).

Abstract: A method and apparatus for facilitating direct access to a parallel Advanced Technology Attachment (ATA) device by an autonomous subsystem in the absence of the main operating system (OS).

Abstract: A method and apparatus for facilitating direct access to a parallel Advanced Technology Attachment (ATA) device by an autonomous subsystem in the absence of the main operating system (OS).

Abstract: A method and apparatus for facilitating direct access to a serial Advanced Technology Attachment (ATA) device by an autonomous subsystem in the absence of the main operating system (OS).

Abstract: The present invention provides a method and apparatus for splitting a bus target response between two devices in a computer system. In one embodiment, the computer system includes a bus having a first signal line and a second signal line, a third signal line, and two agents coupled to the bus and the third signal line. The first agent claims to be a target of a transaction on the bus without decoding the address associated with the transaction by asserting the first signal on the first signal line. The second agent responds to the transaction as the target. The second agent thereafter asserts a third signal on the third signal line to coordinate deassertion of the first signal on the first signal line by the first agent and concurrent assertion of the second signal on the second signal line by the second agent.

Abstract: A computer system has a first bus, a first bus bridge, and a second bus bridge. The first bridge connects the first bus to a second bus and the second bridge connects the first bus to a third bus. Normally, the first bridge behaves as the only subtractive decode agent on the first bus, claiming all transactions initiated on the first bus that target agents on the second bus or the third bus. If the first bridge claims a transaction targetting an agent on the third bus, the first bridge transfers the responsibility to respond to the transaction to the second bridge. The first bridge does not behave as the subtractive decode agent on the first bus when transactions are initiated on the second bus and forwarded to the first bus. In that case, the second bridge behaves as the subtractive decode agent on the first bus.