Processor Status, DDATA Definition

Table 29-22. PST/DDATA Specification for User-Mode Instructions (continued)

Instruction

Operand Syntax

PST/DDATA

 

 

 

wddata.b

<ea>y

PST = 0x4, {PST = 0x8, DD = source operand

 

 

 

wddata.l

<ea>y

PST = 0x4, {PST = 0xB, DD = source operand

 

 

 

wddata.w

<ea>y

PST = 0x4, {PST = 0x9, DD = source operand

 

 

 

1For 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).

2For 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.

3During normal exception processing, the PST 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 Processing PST

=

0xC,

{PST = 0xB,DD = destination},

// stack frame

 

 

 

{PST = 0xB,DD

=

destination},

// stack frame

 

 

 

{PST =

0xB,DD

=

source},

//

vector read

PST

=

0x5,

{PST =

[0x9AB],DD = target}

//

handler PC

The PST/DDATA specification for the reset exception is shown below:

Exception Processing PST

=

0xC,

 

 

PST

=

0x5,

{PST = [0x9AB],DD = 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 PST = 0xC value is driven at all times, unless the PST output is needed for one of the optional marker values or for the taken branch indicator (0x5).

Table 29-23shows the PST/DDATA specification for multiply-accumulate instructions.

Table 29-23. PST/DDATA Specification for MAC Instructions

Instruction

Operand Syntax

PST/DDATA

 

 

 

mac.l

Ry,Rx,Accx

PST = 0x1

 

 

 

mac.l

RyRx,<ea>,Rw,Accx

PST = 0x1, {PST = 0xB, DD = source operand}

 

 

 

mac.w

Ry,Rx,Accx

PST = 0x1

 

 

 

mac.w

Ry,Rx,<ea>,Rw,Accx

PST = 0x1, {PST = 0xB, DD = source operand}

 

 

 

move.l

<ea>y,Accx

PST = 0x1

 

 

 

move.l

Accy,Accx

PST = 0x1

 

 

 

move.l

<ea>y,MACR

PST = 0x1

 

 

 

move.l

<ea>y,MASK

PST = 0x1

 

 

 

move.l

<ea>y,Accext01

PST = 0x1

 

 

 

move.l

<ea>y,Accext23

PST = 0x1

 

 

 

MOTOROLA

Chapter 29. Debug Support

29-43

Page 715
Image 715
Motorola MCF5281, MCF5282 user manual PST/DDATA Specification for MAC Instructions