MPC555
/
MPC556
CENTRAL PROCESSING UNIT
MOTOROLA
USER’S MANUAL
Rev. 15 October 2000
3-52
For L-bus breakpoint instances, these registers are set to:
Execution resumes at offset from the base address indicated by MSR
IP
as follows:
• 0x01D00 – For instruction breakpoint match
• 0x01C00 – For data breakpoint match
• 0x01E00 – For development port maskable request or a peripheral breakpoint
• 0x01F00 – For development port non-maskable request
3.15.4.16 Partially Executed Instructions
In general, the architecture permits instructions to be partially executed when an align-
ment or data storage interrupt occurs. In the core, instructions are not executed at all
if an alignment interrupt condition is detected and data storage interrupt is never gen-
erated by the hardware. In the MPC555 / MPC556, the instruction can be partially ex-
ecuted only in the case of the load/store instructions that cause multiple access to the
memory subsystem. These instructions are:
Register Name
Bits
Description
Save/Restore Register 0 (SRR0)
For I-breakpoints, set to the effective address of the instruc-
tion that caused the interrupt. For L-breakpoint, set to the ef-
fective address of the instruction following the instruction that
caused the interrupt. For development port maskable request
or a peripheral breakpoint, set to the effective address of the
instruction that the processor would have executed next if no
interrupt conditions were present. If the development port re-
quest is asserted at reset, the value of SRR0 is undefined.
Save/Restore Register 1 (SRR1)
1:4
Set to 0
10:15
Set to 0
Other
Loaded from bits 16:31 of MSR. In the current implementa-
tion, Bit 30 of the SRR1 is never cleared, except by loading a
zero value from MSR
RI
.
If the development port request is asserted at reset, the value
of SRR1 is undefined.
Machine State Register (MSR)
IP
No change
ME
No change
LE
Bit is copied from ILE
Other
Set to 0
Register Name
Bits
Description
BAR
Set to the effective address of the data access as computed
by the instruction that caused the interrupt
DAR and DSISR
Do not change
F
re
e
sc
a
le
S
e
m
ic
o
n
d
u
c
to
r,
I
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
n
c
.
..