Digital Equipment DECstation 5000/100 Series, Maintenance Manual

Page: 369 / 392

Diagnostic Status Field
The Diagnostic Status field has the
following format:
24 23 22 21 20 19 18 17 16
+----+-----+--+--+--+--+--+--+
| 0
| BEV |TS|SR|0 |CH|CE|DE|
+----+-----+--+--+--+--+--+--+
2 1 1 1 1 1 1 1
The following Table E-5 describes the Diagnostic Status Fields:
Table E-5. Diagnostic Status Fields
Field Description
BEV Controls the location of TLB refill and general exception
vectors. (0 -> normal; 1 -> bootstrap)
TS TLB shutdown has occurred (read-only)
SR A soft reset has occurred
CH "Hit" (tag match and valid state) or "miss" indication for
last CACHE Hit Invalidate, Hit Write Back Invalidate, Hit
Write Back, Hit Set Virtual, or Create Dirty Exclusion for a
secondary cache.
CE Contents of the ECC register are used to set or modify the
check bits of the caches when CE equals 1.
DE Specifies that cache parity or ECC errors are not to cause
exceptions
0 Reserved. Must be written as zeroes, returns zeroes when
read
BadVAddr Register (R3000 and R4000)
The bad virtual address (BadVAddr) register for the R3000
and R4000 is a 32-bit read-only register that contains the most
recently translated virtual address for which a translation error
occurred. The bad virtual address register has the following
format:
+---------------------------------------------------+
|
BadVAddr |
+---------------------------------------------------+
BadVAddr is the bad virtual address.
CPU and System Registers E–13