Freescale Semiconductor PowerQUICC MPC885 Reference Manual page 203

Table 6-10. Register Settings After a System Call Exception
Register
SRR0 Set to the effective address of the instruction following the System Call instruction
SRR1 0 Loaded with equivalent bits from the MSR
1–4 Cleared
5–9 Loaded with equivalent bits from the MSR
10–15 Cleared
16–31 Loaded with equivalent bits from the MSR
Note that depending on the implementation, reserved bits in the MSR may not be copied to SRR1.
MSR POW 0
ILE —
EE 0
PR 0
When a system call exception is taken, instruction execution resumes at offset 0x00C00 from the physical
base address indicated by MSR[IP].
6.1.2.10 Trace Exception (0x00D00)
A trace exception occurs if MSR[SE] = 1 and any instruction except rfi is successfully completed or if
MSR[BE] = 1 and a branch is completed. Notice that the trace exception does not occur after an instruction
that causes an exception. The monitor/debugger software must change the vectors of other possible
exception addresses to single-step these instructions. If this is unacceptable, other debug features can be
used. See Chapter 53, "System Development and Debugging,"
register settings for trace exceptions.
Register
SRR0 Set to the EA of the instruction following the executed instruction.
SRR1 1–4 0
10–15 0
Others Loaded from MSR[16-31]. SRR1[30] is cleared only by loading a zero from MSR[RI].
MSR IP No change
ME No change
LE Copied from the ILE setting of the interrupted process
Other 0
Execution resumes at offset 0x00D00 from the base address indicated by MSR[IP].
6.1.2.11 Floating-Point Assist Exception
The floating-point assist exception is not generated by the MPC885. Attempting to execute a floating-point
causes an instruction implementation-specific software emulation exception.
Freescale Semiconductor
Setting Description
FP 0
ME —
SE 0
BE 0
Table 6-11. Register Settings After a Trace Exception
MPC885 PowerQUICC Family Reference Manual, Rev. 2
IP — LE
IR 0
DR 0
RI 0
for more information.
Setting
Exceptions
Set to value of ILE
Table 6-11 shows
6-11