Freescale Semiconductor MCF54455 Reference Manual page 903

Debug Module
1
During normal exception processing, the PSTDDATA output is driven to a 0xCC indicating the exception processing state.
The exception stack write operands, as well as the vector read and target address of the exception handler may also be
displayed.
Exception Processing:
PSTDDATA = 0xCC,
{0xB,destination},
{0xB,destination},
{0xB,source},
PSTDDATA = 0x5,{[0x9AB],target}
The PSTDDATA specification for the reset exception is shown below:
Exception Processing:
PSTDDATA = 0xCC,
PSTDDATA = 0x5,{[0x9AB],target}
The initial references at address 0 and 4 are never captured nor displayed because these accesses are treated as
instruction fetches.
For all types of exception processing, the PSTDDATA = 0xCC value is driven at all times, unless the PSTDDATA output
is needed for one of the optional marker values or for the taken branch indicator (0x5).
2
For JMP and JSR instructions, the optional target instruction address is displayed only for those effective address fields
defining variant addressing modes. This includes the following <ea>x values: (An), (d16,An), (d8,An,Xi), (d8,PC,Xi).
3
For move multiple instructions (MOVEM), the processor automatically generates line-sized transfers if the operand
address reaches a 0-modulo-16 boundary and there are four or more registers to be transferred. For these line-sized
transfers, the operand data is never captured nor displayed, regardless of the CSR value.
The automatic line-sized burst transfers are provided to maximize performance during these sequential memory access
operations.
Table 34-33 shows the PSTDDATA specification for multiply-accumulate instructions.
Table 34-33. PSTDDATA Values for User-Mode Multiply-Accumulate Instructions
Instruction
mac.l
mac.l
mac.w
mac.w
move.l
move.l
move.l
move.l
move.l
move.l
move.l
move.l
move.l
move.l
move.l
34-61
Operand Syntax
Ry,Rx,ACCx
Ry,Rx,<ea>y,Rw,ACCx
Ry,Rx,ACCx
Ry,Rx,ea,Rw,ACCx
{Ry,#<data>},ACCx
{Ry,#<data>},MACSR
{Ry,#<data>},MASK
{Ry,#<data>},ACCext01
{Ry,#<data>},ACCext23
ACCext01,Rx
ACCext23,Rx
ACCy,ACCx
ACCy,Rx
MACSR,CCR
MACSR,Rx
// stack frame
// stack frame
// vector read
// handler PC
// handler PC
PSTDDATA Nibble
PSTDDATA = 0x1
PSTDDATA = 0x1, {0xB, source operand}
PSTDDATA = 0x1
PSTDDATA = 0x1, {0xB, source operand}
PSTDDATA = 0x1
PSTDDATA = 0x1
PSTDDATA = 0x1
PSTDDATA = 0x1
PSTDDATA = 0x1
PSTDDATA = 0x1
PSTDDATA = 0x1
PSTDDATA = 0x1
PSTDDATA = 0x1
PSTDDATA = 0x1
PSTDDATA = 0x1
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