INSTRUCTION DESCRIPTIONS
A - 222 INSTRUCTION SET DETAILS MOTOROLA
A MOVEP instruction which specifies SSH as the source operand or LA, LC, SSH, SSL,
or SP as the destination operand cannot be used immediately before a DO instruc-
tion.
A MOVEP instruction which specifies SSH as the source operand or LA, LC, SR, SSH,
SSL, or SP as the destination operand cannot be used immediately before an
ENDDO instruction.
A MOVEP instruction which specifies SSH as the source operand or SR, SSH, SSL, or
SP as the destination operand cannot be used immediately before an RTI instruction.
A MOVEP instruction which specifies SSH as the source operand or SSH, SSL, or SP
as the destination operand cannot be used immediately before an RTS instruction.
A MOVEP instruction which specifies SP as the destination operand cannot be used
immediately before a MOVEC, MOVEM, or MOVEP instruction which specifies SSH or
SSL as the source operand.
Example: :
MOVEP #1113,X:<<$FFFE :initialize Bus Control Register wait states
:
Explanation of Example: Prior to execution, the 16-bit, X memory-mapped, I/O bus
control register (BCR) contains the value $FFFF. The execution of the MOVEP
#$1113,X:<<$FFFE instruction moves the value $1113 into the 16-bit bus control regis-
ter X:$FFFE, resulting in one wait state for all external X, external Y, and external pro-
gram memory accesses and three wait states for all external I/O accesses.
MOVEP Move Peripheral Data MOVEP
Before Execution After Execution
X:$FFFE
(BCR) $FFFF $1113
X:$FFFE
(BCR)