Motorola DSP56000, 24-Bit Digital Signal Processor manual Movem

INSTRUCTION DESCRIPTIONS

MOVEM

Move Program Memory

MOVEM

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.

MOTOROLA INSTRUCTION SET DETAILS A - 215