Installation guide

Registers
There are two types of registers: CPU registers
and system registers. CPU register information
is automatically displayed on the screen when an
exception occurs. To access system registers from
the console prompt (>>), enter the e command.
Cause register
The cause register is a CPU register and is
displayed in exception error messages only. You
cannot access the cause register independently.
The cause register has the following format:
31 30 29 28 27 16
+----+---+-----+-----------------+
|BD|0|CE | 0 |
+----+---+-----+-----------------+
112 12
15 87 65 21 0
+------------+----+---------+----+
| IP | 0 | ExcCode | 0 |
+------------+----+---------+----+
8242
BD = 1 Indicates that the last exception
occurred in a branch delay slot
CE The coprocessor unit number
reference for a coprocessor unusable
exception
IP = 1 Indicates that an interrupt is pending
ExcCode Shows the exception code. See
Table 1-7.
0 Reserved.
1–16 TROUBLESHOOTING INFORMATION