User guide

4
Diagnostics
4.1 Overview
This chapter describes the Digital Alpha VME 4 power-on self-test (POST)
diagnostics and additional ROM-based diagnostics (RBDs).
Diagnostics for the Digital Alpha VME 4 system provide a fast, high coverage
suite of POSTs to be invoked automatically at power-on and system reset. In
addition to the POSTs, there are RBDs that provide additional testing and fault
isolation. You invoke RBDs at the console prompt from the console terminal.
You can use diagnostic environment variables to gain more control of the test
environment.
4.2 Operating Environments
The Digital Alpha VME 4 diagnostics are invoked under two distinct mechanisms:
• Power-on and/or system reset
• By an operator at the console prompt
4.2.1 POST Diagnostics
The diagnostic reset environment is entered as a result of power being applied to
the system or, reset being applied to a previously running system. In this mode,
a sequence of RBDs is executed without user intervention.
Once the SROM code has been loaded into the 8 KB internal instruction cache,
a very basic system initialization is performed in preparation for starting the
console firmware. After enough of the system has been initialized, the flash ROM-
based console is loaded into system memory and execution is transferred to it.
During this phase of console startup, several more diagnostics are automatically
invoked and executed without operator intervention.
The system LED display indicates progress of the SROM initialization. The
display counts down from 8 to 1.
Diagnostics 4–1