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EMAC Instruction Set Summary
3.5
EMAC Instruction Set Summary
Table 3-3 summarizes EMAC unit instructions.
Command
Multiply Signed
MULS <ea>y,Dx
Multiply Unsigned
MULU <ea>y,Dx
Multiply Accumulate
MAC Ry,RxSF,ACCx
MSAC Ry,RxSF,ACCx
Multiply Accumulate
MAC Ry,Rx,<ea>y,Rw,ACCx
with Load
MSAC Ry,Rx,<ea>y,Rw,ACCx
Load Accumulator
MOV.L {Ry,#imm},ACCx
Store Accumulator
MOV.L ACCx,Rx
Copy Accumulator
MOV.L ACCy,ACCx
Load MACSR
MOV.L {Ry,#imm},MACSR
Store MACSR
MOV.L MACSR,Rx
Store MACSR to CCR
MOV.L MACSR,CCR
Load MAC Mask Reg
MOV.L {Ry,#imm},MASK
Store MAC Mask Reg
MOV.L MASK,Rx
Load AccExtensions01
MOV.L {Ry,#imm},ACCext01
Load AccExtensions23
MOV.L {Ry,#imm},ACCext23
Store AccExtensions01
MOV.L ACCext01,Rx
Store AccExtensions23
MOV.L ACCext23,Rx
3.5.1
EMAC Instruction Execution Times
The instruction execution times for the EMAC can be found in Section 2.12, "EMAC
Instruction Execution Times."
The EMAC execution pipeline overlaps the AGEX stage of the OEP; that is, the first stage
of the EMAC pipeline is the last stage of the basic OEP. EMAC units are designed for
sustained, fully-pipelined operation on accumulator load, copy, and multiply-accumulate
instructions. However, instructions that store contents of the multiply-accumulate
programming model can generate OEP stalls that expose the EMAC execution pipeline
depth, as in the following:
mac.w
Ry, Rx, Acc0
mov.l
Acc0, Rz
3-12
Table 3-3. EMAC Instruction Summary
Mnemonic
Multiplies two signed operands yielding a signed result
Multiplies two unsigned operands yielding an unsigned result
Multiplies two operands and adds/subtracts the product to/from an
accumulator
Multiplies two operands and combines the product to an
accumulator while loading a register with the memory operand
Loads an accumulator with a 32-bit operand
Writes the contents of an accumulator to a CPU register
Copies a 48-bit accumulator
Writes a value to MACSR
Write the contents of MACSR to a CPU register
Write the contents of MACSR to the CCR
Writes a value to the MASK register
Writes the contents of the MASK to a CPU register
Loads the accumulator 0,1 extension bytes with a 32-bit operand
Loads the accumulator 2,3 extension bytes with a 32-bit operand
Writes the contents of accumulator 0,1 extension bytes into a CPU
register
Writes the contents of accumulator 2,3 extension bytes into a CPU
register
MCF5282 User's Manual
Description
MOTOROLA
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