User's Manual

PMAC2 PCI Lite Hardware Reference Manual – Preliminary Documentation
PMAC2 PCI Lite Jumper Descriptions 15
JUMPER DESCRIPTIONS
E1: Servo and Phase Clock Direction Control
E Point and
Physical Layout
Location Description Default
E1
C2 Remove jumper for PMAC2 PCI Lite to use its
internally generated servo and phase clock signals and
to output these signals on the J5A serial port connector.
Jump pins 1 and 2 for PMAC2 PCI Lite to expect to
receive its servo and phase clock signals on the J5A
serial port connector.
No jumper installed
Note: If the E1 jumper is ON and the servo and phase clocks are not brought in on the J5A serial port, the
watchdog timer will trip immediately.
E2: CPU Frequency Select
E Point and
Physical Layout
Location Description Default
E2
C2 Remove jumper for 40MHz operation (E4 OFF also) or
for 80MHz operation (E4 ON) with I46 = 0.
Jump pin 1 to 2 for 60MHz operation (E4 OFF) with
I46 = 0.
Not used if I46 > 0.
No jumper installed
Jumper installed
E3: Normal/Re-Initializing Power-Up/Reset
E Point and
Physical Layout
Location Description Default
E3
C2 Jump pin 1 to 2 to re-initialize on power-up/reset,
loading factory default settings.
Remove jumper for normal power-up/reset, loading
user-saved settings.
No jumper installed
E4: CPU Frequency Select
E Point and
Physical Layout
Location Description Default
E4
C2 Remove jumper for 40MHz operation (E2 OFF also) or
for 60MHz operation (E4 ON) with I46 = 0.
Jump pin 1 to 2 for 80MHz operation (E2 OFF) with
I46 = 0.
Not used if I46 > 0
No jumper installed
(standard or Opt 5B)
Jumper installed (Opt
5C)
E5 – E6: (Reserved for Future Use)