Jumpers; Cpu Clock Speed Selection - Jp5 And Jp6 - Shuttle HOT-681 User Manual

Jumpers

Several hardware settings are made through the use of jumper caps to connect jumper pins on
the main board. The jumper's pin 1 on main board will be on the top or on the left when hold-
ing the main board with the keyboard connector away from yourself.
Jumpers with two pins will be shown as
To connect the pins, simply place a plastic jumper cap over the two pins.
CPU Clock Speed and ratio Selection - JP5 and JP6
HOT-681 mainboard features a clock generator to provide adjustable system clock frequency.
JP5 is a 6-pin jumpers which determine the system clock frequency 66 MHz to 133 MHz. and
JP6 is a 8-pin jumper which determine the processor clock ratio from 3.5X to 8X.
Figure 2-4 shows the position of JP5 and JP6 on the mainboard.
Table 2-1 shows adjustable System clock
on jumper JP5.
Table 2-2, 2-3 and 2-4 shows adjustable
CPU Clock Ratios on jumper group JP6.
System Clock
66 MHz
75 MHz
83 MHz
100 MHz
103 MHz
112 MHz
133 MHz
Table 2-1
Multiplier JP6
3.5X
4X
4.5X
5X
Table 2-2
for Close (On) and
JP5
Figure 2-3
(100)
Multiplier
MHz
350
4.5X
400
5X
450
5.5X
500
6X
Table 2-3
- 9 -
for Open (Off).
(66)
Multiplier
JP6
MHz
6.5X
300
7X
333
7.5X
366
8X
400
Table 2-4
(66)
JP6
MHz
433
466
500