Central Processing Unit
MPC561/MPC563 Reference Manual, Rev. 1.2
Freescale Semiconductor
3-49
The interrupt may be delayed by other higher priority exceptions or if the MSR[EE] bit is cleared when
the exception occurs. MSR[EE] is automatically cleared by hardware to disable external interrupts when
any exception is taken.
Upon detecting an external interrupt, the processor assigns it to the instruction at the head of the history
buffer (after retiring all instructions that are ready to retire).
The enhanced interrupt controller mode is available for interrupt-driven applications on
MPC561/MPC563. It allows the single external interrupt exception vector 0x500 to be split into up to 48
different vectors corresponding to 48 interrupt sources to speed up interrupt processing. It also supports a
low priority source masking feature in hardware to handle nested interrupts more easily. See
“Enhanced Interrupt Controller
Chapter 4, “Burst Buffer Controller 2 Module
.”
The register settings for the external interrupt exception are shown in
.
When an external interrupt is taken, instruction execution resumes at offset 0x00500 from the physical
base address indicated by MSR[IP].
3.15.4.6
Alignment Exception (0x00600)
The following conditions cause an alignment exception:
•
The operand of a floating-point load or store instruction is not word-aligned.
•
The operand of a load or store multiple instruction is not word-aligned.
•
The operand of lwarx or stwcx. is not word-aligned.
Alignment exceptions use the SRR0 and SRR1 to save the machine state and the DSISR to determine the
source of the exception.
The register settings for alignment exceptions are shown in
.
Table 3-26. Register Settings following External Interrupt
Register
Bits
Setting Description
Save/Restore Register 0 (SRR0)
1
1
If the exception occurs during an instruction fetch in Decompression On mode, the SRR0 register will contain an
address in compressed format.
All
Set to the effective address of the instruction that the processor would
have attempted to execute next if no interrupt conditions were present.
Save/Restore Register 1 (SRR1)
[0:15]
Cleared to 0
[16:31]
Loaded from bits [16:31] of MSR. In the current implementation, bit 30
of the SRR1 is never cleared, except by loading a zero value from
MSR[RI]
Machine State Register (MSR)
IP
No change
ME
No change
LE
Set to value of ILE bit prior to the exception
DCMPE
N
This bit is set according to (BBCMCR[EN_COMP] AND
BBCMCR[EXC_COMP])
Other
Cleared to 0
Summary of Contents for MPC561
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Page 206: ...Central Processing Unit MPC561 MPC563 Reference Manual Rev 1 2 3 62 Freescale Semiconductor...
Page 302: ...Reset MPC561 MPC563 Reference Manual Rev 1 2 7 14 Freescale Semiconductor...
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