Patent ID: 6292859
Filing Date: 2001-09-18
Classification: G06F

Abstract:
A computer system having on-board peripheral controllers and provisions for adding upgrade peripheral controllers, said system comprising:a computer system motherboard;a central processing unit connected to a host bus on said motherboard;a random access memory connected to a random access memory bus on said motherboard;an on-board peripheral controller connected to a peripheral bus on said motherboard;a connector adapted to receive an upgrade peripheral controller, said connector connected to said peripheral bus;a core logic chipset connected to said host bus, said random access memory bus and said peripheral bus;a first logic circuit for holding said on-board peripheral controller in reset;said first logic circuit having an output connected to a reset input of said on-board peripheral controller, a first input connected to a reset signal of said computer system and a second input for controlling whether the output of said logic circuit maintains an asserted reset signal logic level on the reset input of said on-board peripheral controller or the output follows the logic levels of the reset signal of said computer system; anda second logic circuit for generating a disable signal to the second input of said first logic circuit, whereinthe disable signal is asserted during initial startup of said computer system so that the output of said first logic circuit maintains the asserted reset signal logic level on the reset input of said on-board peripheral controller while the computer system determines whether an upgrade peripheral controller is present in said connector,if the upgrade peripheral controller is determined to be present in said connector then the computer system configures the upgrade peripheral controller and continues to maintain the asserted disable signal, andif the upgrade peripheral controller is not present in said connector then the disable signal is deasserted and the computer system configures said on-board peripheral controller.