Patent ID: 7796457

Claim:
A motherboard comprising: a first slot arranged for mounting a first type of memory; a second slot arranged for mounting a second type of memory, the first memory and the second memory alternatively mounted on the motherboard; a voltage regulator electronically connected to the first slot and the second slot, wherein the voltage regulator comprises a controller and a feedback circuit, the controller comprises a feedback pin and an output end, a first voltage at the feedback pin is a feedback voltage; and a serial presence detect (SPD) unit connected to the voltage regulator configured for detecting which type of memory is mounted on the motherboard and controlling status of the feedback circuit, wherein a first end of the feedback circuit is connected to the SPD unit, a second end of the feedback circuit is connected to the feedback pin of the controller, a third end of the feedback circuit is operable to receive a second voltage from the output end of the controller, the controller changes the second voltage output to the third end of the feedback circuit and the first or second slot to ensure the feedback voltage being equal to a third voltage at the second end of the feedback circuit.