Aaeon SBC-656 User Manual page 30

CPU core frequency = CPU frequency ratio (3~5.5) * External bus
clock (66 or 100 MHz)
CPU frequency ratio select SW1 (D, E, F)
* default
Most Celeron CPUs' frequency ratio are pre-locked
within the CPUs. Thess CPUs run at fixed speed
(frequency) regardless of the configurations listed above.
If the CPU you are using requires higher ratio then 5.5X, it
is most likely pre-locked.
20 SBC-656 User Manual
3X
A
B
C
D
E
F
4.5X *
A
B
C
D
E
F
3.5X
A
B
C
D
E
F
5 X
A
B
C
D
E
F
4.0X
A
B
C
D
E
F
5.5X
A
B
C
D
E
F