Hardware Installation
2-8
JP12
1-2
3-4
I/O Voltage (Vio)
3.3 (default)
3.45V
JP12
is reserved for testing purposes only.
This jumper enables you to set the voltage of
the onboard chipset and PBSRAM (Vio). For
dual-voltage CPU, JP12 also functions as
CPU I/O voltage (Vcpuio) controller.
JP12
1 2 3
3.3V
(default)
JP12
1 2 3
3.45V
2.2.2 Selecting the CPU Frequency
Intel Pentium, Cyrix 6x86, AMD K5/K6 and IDT C6 CPU are designed to have
different Internal (Core) and External (Bus) frequency.
Core frequency = Ratio * External bus clock
S1
OFF
ON
ON
OFF
ON
ON
OFF
S2
OFF
OFF
ON
ON
OFF
ON
ON
S3
OFF
OFF
OFF
OFF
ON
ON
ON
CPU Frequency
Ratio
1.5x (3.5x)
2x
2.5x (1.75x)
3x
4x
4.5x
5x
The ratio of Core/Bus frequency
is selected by the switch 1-3 of
SW1
.
Note:
Intel PP/MT MMX 233MHz is using 1.5x jumper setting
for 3.5x frequency ratio, and AMD PR166 is using 2.5x
setting for 1.75x frequency ratio.
