user manual

INSTRUCTION DESCRIPTIONS
MOTOROLA INSTRUCTION SET DETAILS A - 215
operands, both the automatic sign-extension and zeroing features may be disabled by
specifying the destination register to be one of the individual 24-bit accumulator registers
(A1 or B1).
Note: Due to instruction pipelining, if an AGU register (Mn, Nn, or Rn) is directly changed
with this instruction, the new contents may not be available for use until the second fol-
lowing instruction. See the restrictions discussed in A.9.6 - R, N, and M Register Restric-
tions on page A-page 310.
Restrictions: The following restrictions represent very unusual operations, which proba-
bly would never be used but are listed only for completeness.
A MOVEM instruction used within a DO loop which specifies SSH as the source oper-
and or LA, LC, SR, SP, SSH, or SSL as the destination operand cannot begin at the
address LA–2, LA–1, or LA within that DO loop.
A MOVEM 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
instruction.
A MOVEM instruction which specifies SSH as the source operand or LA, LC, SR, SSH,
SL, or SP as the destination operand cannot be used immediately before an ENDDO
instruction.
A MOVEM 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 MOVEM 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 MOVEM 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.
MOVEM Move Program Memory MOVEM