Selecting The Cpu Frequency - AOpen AP5TC User Manual

Hardware Installation
JP12 I/O Voltage (Vio)
1-2 3.3 (default)
3-4 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 S2
OFF OFF
ON OFF
ON ON
OFF ON
ON OFF
ON ON
OFF ON
2-8
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.
S3 CPU Frequency
Ratio
OFF 1.5x (3.5x)
OFF 2x
OFF 2.5x (1.75x)
OFF 3x
ON 4x
ON 4.5x
5x
ON
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.
JP12
1 2 3
3.3V
(default)
The ratio of Core/Bus frequency
is selected by the switch 1-3 of
SW1.
JP12
1 2 3
3.45V