SOYO P55C, P54C manual Remarks on the Cyrix and IBM P200+ CPUs

Introduction 5

Remarks on the Cyrix and IBM P200+ CPUs

Please note that if you use a Cyrix or IBM P200+ CPU, you will have to set the frequency to 75MHz. You will also have to set JP16, the PCI bus frequency jumper to asynchronous to have the PCI bus run on 32MHz, in order to avoid problems with add-on cards. If you choose to run the PCI bus on a higher frequency, please use only high-end add-on cards that are specified to function on higher bus frequencies. Please note that using a 75MHz bus clock also places higher demands on the DRAM main-memory, therefore only use high-end SIMM/DIMM modules when this is the case.

Voltage settings list

Jumpers 30, 31 and 32 set the processor voltage. If you are using a single voltage processor close jp31 and open jp30. Jp31 shorts the processor Vcore voltage pins to the Vio pins when closed. If you use a dual voltage CPU, open jp31 and close jp30.

Jp 32 sets the voltage, please refer to the following table:

voltage			JP32
	1-2	3-4		5-6	7-8
3.5V	close	close		close	close
3.4V	close	close		close	open
3.3V	close	close		open	close
3.2V	close	close		open	open
3.1V	close	open		close	close
3.0V	close	open		close	open
2.9V	close	open		open	close
2.8V	close	open		open	open
2.7V	open	close		close	close
2.6V	open	close		close	open
2.5V	open	close		open	close
2.4V	open	close		open	open
2.3V	open	open		close	close
2.2V	open	open		close	open
2.1V	open	open		open	close
2.0V	open	open		open	open