4-4
MPC7400 RISC Microprocessor Users Manual
MPC7400 Microprocessor Exceptions
Alignment
00600
¥ A oating-point load/store,
stmw
,
stwcx.
,
lmw
,
lwarx
,
eciwx
, or
ecowx
instruction operand is not word-aligned.
¥ A multiple/string load/store operation is attempted in little-endian mode
¥ An operand of a
dcbz
instruction is on a page that is write-through or
cache-inhibited for a virtual mode access.
¥ An attempt to execute a
dcbz
instruction occurs when the cache is
disabled or locked.
Program
00700
As speciTed in the PowerPC architecture
Floating-point
unavailable
00800
As speciTed in the PowerPC architecture
Decrementer
00900
As deTned by the PowerPC architecture, when the most-signiTcant bit of the
DEC register changes from 0 to 1 and MSR[EE] = 1
Reserved
00A00D00BFF
System call
00C00
Execution of the System Call (
sc
) instruction
Trace
00D00
MSR[SE] =1 or a branch instruction is completing and MSR[BE] =1. The
MPC7400 differs from the OEA by not taking this exception on an
isync
.
Reserved
00E00
The MPC7400 does not generate an exception to this vector. Other PowerPC
processors may use this vector for oating-point assist exceptions.
Reserved
00E10D00EFF
Performance monitor
00F00
The limit speciTed in PMC
n
is met and MMCR0[ENINT] = 1
(MPC7400-speciTc)
AltiVec unavailable
00F20
Occurs due to an attempt to execute any nonstreaming AltiVec instruction
when MSR[VEC] = 0. This exception is not taken for data streaming
instructions (
dst
x
,
dss,
or
dssall
). (MPC7400-speciTc)
Instruction address
breakpoint
01300
IABR[0D29] matches EA[0D29] of the next instruction to complete, IABR[TE]
matches MSR[IR], and IABR[BE] = 1 (MPC7400-speciTc)
System management
interrupt
01400
MSR[EE] = 1 and SMI is asserted (MPC7400-speciTc)
Reserved
01500D015FF
AltiVec assist
01600
This MPC7400-speciTc exception supports denormalization detection in Java
mode as speciTed in the
AltiVec Technology Programming Environments
Manual
.
Reserved
01700
The MPC7400 does not generate an exception to this vector. Other PowerPC
processors may use this vector for thermal management interrupts.
Thermal
management
01700
Generated when the thermal management assist unit detects the temperature
has exceeded the programmed threshold.
Reserved
01800D02FFF
Table 4-2. Exceptions and Conditions (Continued)
Exception Type
Vector Offset
(hex)
Causing Conditions