Circuit Board Reference Manual

MCF548x Reference Manual, Rev. 3
8-58 Freescale Semiconductor
Table 8-31 shows the PSTDDATA specification for multiply-accumulate instructions.
1
During normal exception processing, the PSTDDATA output is driven to a 0xC 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 ProcessingPSTDDATA = 0xC,{0xB,destination},// stack frame
{0xB,destination},// stack frame
{0xB,source},// vector read
PSTDDATA = 0x5,{[0x9AB],target}// handler PC
The PSTDDATA specification for the reset exception is shown below:
Exception ProcessingPSTDDATA = 0xC,
PSTDDATA = 0x5,{[0x9AB],target}// handler PC
The initial references at address 0 and 4 are never captured nor displayed since these accesses are treated
as instruction fetches.
For all types of exception processing, the PSTDDATA = 0xC 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 8-31. PSTDDATA Values for User-Mode Multiply-Accumulate Instructions
Instruction Operand Syntax PSTDDATA
mac.l Ry,Rx PSTDDATA = 0x1
mac.l Ry,Rx,<ea>y,Rw,ACCx PSTDDATA = 0x1,{0xB, source operand}
mac.l Ry,Rx,ACCx PSTDDATA = 0x1
mac.l Ry,Rx,ea,Rw PSTDDATA = 0x1,{0xB, source operand}
mac.w Ry,Rx PSTDDATA = 0x1
mac.w Ry,Rx,<ea>y,Rw,ACCx PSTDDATA = 0x1,{0xB, source operand}
mac.w Ry,Rx,ACCx PSTDDATA = 0x1
mac.w Ry,Rx,ea,Rw PSTDDATA = 0x1,{0xB, source operand}
move.l {Ry,#<data>},ACCext01 PSTDDATA = 0x1
move.l {Ry,#<data>},ACCext23 PSTDDATA = 0x1
move.l {Ry,#<data>},ACCx PSTDDATA = 0x1
move.l {Ry,#<data>},MACSR PSTDDATA = 0x1
move.l {Ry,#<data>},MASK PSTDDATA = 0x1
move.l ACCext01,Rx PSTDDATA = 0x1
move.l ACCext23,Rx PSTDDATA = 0x1
move.l ACCy,ACCx PSTDDATA = 0x1