Patent ID: 6693451
Filing Date: 2004-02-17
Classification: H03K

Abstract:
A main circuit board structure, comprising:a microprocessor connector ready for a microprocessor to plug in, such that as the microprocessor is plugged into the microprocessor connector, a microprocessor signal is, generated, wherein the microprocessor signal indicates one of a plurality of logic bus schemes for the microprocessor; and a chipset having an input/output buffer, wherein the input/output buffer can receive the microprocessor signal and configure the chipset to work under the indicated one of the logic bus schemes, wherein the input/output buffer includes: a logic control circuit, to receive the microprocessor signal and recognize the indicated one of the logic bus schemes; and a resistance adjusting circuit, which comprises a plurality of resistance routes, wherein the resistance adjusting circuit is coupled with and controlled by the logic control circuit, so as to produce an equivalent resistance for the chipset in operation under the indicated one of the logic bus schemes.