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Method to Set the Processor Speed of a Motherboard During System Manufacturing

IP.com Disclosure Number: IPCOM000014959D
Original Publication Date: 2001-Nov-02
Included in the Prior Art Database: 2003-Jun-20

Publishing Venue



Today we are forced to buy a different microprocessor chip/module for each microprocessor speed that we sell in a PC system. This forces us to manage inventory for each speed grade. This publication describes a method to solve this problem by placing a circuit on the motherboard that connects to the microprocessor through dedicated pins to burn a fusible link(s) in the processor. Once the fusible link(s) is(are) blown the processor speed is set forever. This allows us to buy one processor and "program" the speed based upon our orders.This removes our inventory complexity involved with different speed microprocessors. This method consists of two parts. First is the fusible link in the processor. Fusible links are not new to semiconductors. This fusible link drives circuits on the microprocessor die that set the clock speed multiplier (as referenced from the processor front side bus). The second part of this method is the circuits on the motherboard and the unique pins on the micro-processor to blow the fusible link(s). The circuits on the motherboard are used to allow a manufacturing configuration station to apply a voltage, a multiplier setting (the example shown below has 4 bits for 16 settings) and an "enable" signal to the processor to program the clock multiplier. This is done after the processor and heat sink are attached to the board and assembled into the system. Before the system is powered and tested the assembly operator attaches a cable to the motherboard. This cable is driven by hardware which is part of the manufacturing control system. This hardware drives the signals to the microprocessor and programs the frequency. Once the frequency is set the operator removes the cable and the system is powered up and tested normally. The cable connector insures that the ground contact is made first so that no electrostatic discharge damages the system being manufactured. Advantages are that systems can be manufactured and set aside to be programmed later for speed programming and testing as orders are received. Only one type of microprocessor need be planned for, purchased and inventoried by manufacturing. 1 m icro p ro ce sso r n iP s