Service manual

6
The CLEAR EXCEPTION command prints the contents of three
registers (XBER, XFADR, and RCSR) and then clears their error bits,
if set. No error bits have been set at this point.
7
The SHOW CONFIGURATION command attempts to examine unused
address space, creating errors.
8
Issuing the CLEAR EXCEPTION command again shows the contents
of the three registers with error bits set. These error bits are then
cleared by the command. When VAX/DS is halted as it was in
5
of part
2 of this example and a command is issued that causes errors, as in
7
,
the CLEAR EXCEPTION command must be issued before issuing the
CONTINUE command to resume the VAX/DS session.
9
VAX/DS is halted and SHOW CONFIGURATION is issued, again
creating errors. (The response to SHOW CONFIGURATION is the
same as shown in
7
.)
10
This time the CONTINUE command is issued
10
without first issuing
the CLEAR EXCEPTION command. Since error bits were not cleared,
VAX/DS attempts to perform its error recovery procedures, and an
interrupt occurs. This is normal behavior for a <REFERENCE>(rigel)
system in these circumstances.
Diagnostics 2–41