User's Manual

Turbo PMAC PCI HRM
22 Main Board E-Point Descriptions
E48: CPU Clock Frequency Control (Option CPU Section)
E48 controls the CPU clock frequency only on PMAC with an option CPU section using flash memory
backup (no battery). This CPU section is used on PMACs ordered with Opt 4A, 5A, or 5B. The 80 MHz
setting of a CPU section ordered with Opt 5C is performed by software; refer to the Software Configuration
section of this manual.
E Point and
Physical Layout
Location Description Default
E48
C5 Jump pins 1 and 2 to multiply crystal frequency
by three inside CPU for 60-MHz operation.
Remove jumper to multiply crystal frequency by
two inside CPU for 40 MHz operation.
Jumper installed (Option 5, 5B)
Jumper not installed (Standard,
Option 4A, 5A)
Note: It may be possible to operate a board with 40 MHz components (Option 5A) at 60 MHz under some conditions by
changing the setting of jumper E48. However, this operates the components outside of their specified operating range,
and proper execution of PMAC under these conditions is not guaranteed. PMAC software failure is possible, even
probable, under these conditions, and this can lead to very dangerous machine failure. Operation in this mode is done
completely at the user's own risk; Delta Tau cannot accept responsibility for the operation of PMAC or the machine
under these conditions.
E49: Serial Communications Parity Control
E Point and
Physical Layout
Location Description Default
E49
C5 Jump pin 1 to 2 for no serial parity.
Remove jumper for odd serial parity.
Jumper installed
E50: Flash Save Enable/Disable
E Point and
Physical Layout
Location Description Default
E50
C5 Jump pin 1 to 2 to enable save to flash memory.
Remove jumper to disable save to flash
memory.
Jumper Installed
E51: Normal/Re-Initializing Power-Up
E Point and
Physical Layout
Location Description Default
E51
B6 Jump pin 1 to 2 to re-initialize On power-
up/reset;
Remove jumper for Normal power-up/reset.
No jumper installed