Sun Microsystems SUN BLADE 150, Service Manual

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C-14 Sun Blade 150 Service Manual • June 2002
TABLE C-3
lists all the clocks present on the system. Each of the clocks listed is
generated by the clock generator or a dedicated crystal.
C.7.2 OpenBoot PROM Jumpers CPU Speed Selection
When the system is powered on, the CPU clock speed is determined by the default
hardware settings (200MHz) of the MC12429. The OpenBoot PROM firmware then
needs to know the exact CPU speed so that the OpenBoot PROM can reprogram the
MC12429 accordingly through the OpenBoot PROM serial programming interface.
The CPU speeds and jumper settings are provided in the CPU release notes.
FIGURE C-9
shows the jumper settings for the 550 MHz and 650 MHz CPUs.
TABLE C-3
Clock Frequencies
Component Clock Frequency (MHz) Source Description
CPU CLKA 125 ~ 350 Clock generator LVPECL
CPU CLKB 125 ~ 350 Clock generator LVPECL
CPU PCI_REF_
CLK 66.66 Clock generator Core PCI clock
CPU PCI_CLK 33.33 Clock generator PCI clock
SouthBridge PCI_CLK 33.33 Clock generator PCI clock
SouthBridge OSC32KI/ 32.768KHz Dedicated crystal Real-time clock
SouthBridge USB_CLK 48.00 Clock generator USB clock
SouthBridge OSC14M 14.3182 Clock generator Reference clock
Graphics chip Clk 29.499 Dedicated crystal Video clock
Graphics chip PCICLK 33.33 Clock generator PCI clock
PCIO-2.x PCICLK 33.33 Clock generator PCI clock
PCIO-2.x USBCLK 48.00 Clock generator USB clock
IChip2 PCICLK 33.33 Clock generator PCI clock
PCI bridge PCICLK 33.33 Clock generator PCI clock
AC97 XIN 24.576 Dedicated crystal CS4297 clock
1394 PHY XIN 24.576 Dedicated crystal FW802 clock