2-4
2.2
Power-Up Sequence
Console and most power-up tests reside on the I/O subsystem, not on the CPU
nor on any other module on the system bus.
Figure 2-2 Power-Up Flow
SROM tests execute
PKW0432B-96
SRM console loaded
into memory
SROM code loaded
into each CPU’s
I-cache
XSROM tests execute
Power-Up/Reset
SRM console tests
execute
SRM console either
remains in the system
or loads AlphaBIOS
console
XSROM loaded into
each CPU’s S-cache
Definitions
SROM. The SROM is a 128-Kbit ROM on each CPU module. The ROM contains
minimal diagnostics that test the Alpha chip and the path to the XSROM. Once the
path is verified, it loads XSROM code into the Alpha chip and jumps to it.
XSROM. The XSROM, or extended SROM, contains back-up cache and memory
tests, the I/O subsystem tests for imbedded devices, and a fail-safe loader. The
