B-14 UltraEnterprise 6000/5000/4000 Systems Manual—November 1996
B
B.10 Clock BoardThe clock board is located at the rear of the system, directly below the
peripheral power supply.When replacing the clock board, orient the board
with the component side up. See FigureB-10.
The clock board provides 16 pairs of system clocks, 32 pairs of processor
clocks.
All processors runat the same clock speed. The system clock and the processor
clocks arederived from a single clock source. The frequency of the clock source
as well as the processor and system clocks are programmable and set by
firmware. The processor clock frequencyis set to match the lowest-frequency
processor in the system.
The clock board also includes central devices including serial ports, keyboard
and mouse, and a time of day (TOD) chip.
FigureB-10 Clock Board