Sun Microsystems SUN BLADE 150, Service Manual

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Appendix C Functional Description C-17
C.8.3.1 On-Board VRM requirements
The overall solution for the system on-board VRM should be based on the following
requirements:
■
Programmable output from 1.3V to 3.5V
■
5V input source
■
At least 12.5 amps driving capability
C.8.3.2 Power-On Beep
The M1535D SouthBridge provides a speaker output to the audio codec for output to
an internal speaker. This speaker output has two different beep functions, one is
write-beep function that beeps one to three beeps depending on the number of
writes to the register and the other is a periodic four-beep function. This is all
controlled by the software. The OpenBoot PROM must program the M1535D to send
a “beep” sound at power on.
C.8.3.3 Power-On LED Control
The M1535D provides a software-controllable LED output to turn on or turn off the
LED and causes the LED to blink at the rate of 1Hz or 2Hz.
C.8.4 Optional Secondary Hard Drive
The Sun Blade 150 system has a provision for a second hard drive on the hard drive
tray (
FIGURE C-10
).
FIGURE C-10
Secondary Hard Drive Cabling Configuration
Riser Board (J503)
IDE 2
Optional Second Hard Drive
(Secondary HDD)