MOTOROLA
Chapter 3. Central Processing Unit
3-51
Operating Environment Architecture (OEA)
when a machine check exception is taken, instruction execution resumes at offset 0x0200
from the base address indicated by MSR[IP].
3.15.4.3 Data Storage Exception (0x0300)
A data storage exception is never generated by the RCPU. The software may branch to this
location as a result of implementation-specific data storage protection error exception.
3.15.4.4 Instruction Storage Exception (0x0400)
An instruction storage interrupt is never generated by them RCPU. The software may
branch to this location as a result of an implementation-specific instruction storage
protection error exception.
3.15.4.5 External Interrupt (0x0500)
The external interrupt exception is taken on assertion of the internal IRQ line to the RCPU,
that is driven by on-chip interrupt controller. The interrupt may be caused by the assertion
Machine State Register (MSR)
IP
No change
ME
No change
LE
Bit is copied from ILE
DCMPEN
This bit is set according to (BBCMCR[EN_COMP] AND
BBCMCR[EXC_COMP])
Other
Cleared to 0
Data/Storage Interrupt Status
Register (DSISR) 3
0:14
Cleared to 0
15:16
Set to bits [29:30] of the instruction if X-form and to 0b00 if
D-form
17
Set to bit 25 of the instruction if X-form and to Bit 5 if D-form
18:21
Set to bits [21:24] of the instruction if X-form and to bits [1:4] if
D-form
22:31
Set to bits [6:15] of the instruction
Data Address Register (DAR)
3All
Set to the effective address of the data access that caused the
interrupt
1 If the exception occurs due to a data error caused by a Load/Store instruction and the processor in Decompression
On mode, the SRR0 register will contain the address of the Load/Store instruction in compressed format. If the
exception occurs due to an instruction fetch in Decompression On mode, the SRR0 register will contain an
indeterminate value.
2 This bit is loaded from the corresponding bit in the MSR when an interrupt is taken. The appropriate bit in MSR is
loaded from this bit when an RFI is executed.
3 DSISR and DAR registers are only updated when the machine check exception is caused by a data access violation.
Table 3-25. Register Settings following a Machine Check Exception (continued)
Register Name
Bits
Description