Sony 486DX User Manual page 26

AR-B1474 User¡ ¦ s Guide
(4) CPU Clock Select (JP6 & JP9)
For different type of CPUs, the clock generator and clock divisor need to be set by JP6 and JP9. The clock base is
selected by JP6, JP9 is used to select single or half clock system. We recommend that you refer the following
table for setting the CPU clock.
Table 3-6 CPU Clock Setting
3-8
1 2 3
1 2 3
1X
Factory Preset
Figure 3-14 JP9: CPU System Clock Multiplier Select
Pin
1-2
3-4
5-6
Table 3-5 JP6: CPU Base Clock
CPU
CPU Type
Clock
DX-25, DX2-50, 25MHz
DX4-75
DX-33, DX2-66, 33.3MHz 33.3MHz 1X
DX4-100, 5X86-
133
DX-40, DX2-80, 40MHz
DX4-120
DX-50 50MHZ
JP9
1 2 3
1 2 3
2X
2
Definition
A
B
C
1
A
Base
JP9
A
Clock
50MHz 1X Close Open Open
Close Open Close
40MHz 1X Close Close Open
50MHz 1X Close Close Close
4 6
3 5
B C
JP6
Note
B C
Factory
Preset