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Enhanced Multiply-Accumulate Unit (EMAC)
5-13
Freescale Semiconductor
movem.l (a7),#0x00ff
; restore the state from memory
move.l #0,macsr
; disable rounding in the macsr
move.l d0,acc0
; restore the accumulators
move.l d1,acc1
move.l d2,acc2
move.l d3,acc3
move.l d4,accext01
; restore the accumulator extensions
move.l d5,accext23
move.l d6,mask
; restore the address mask
move.l d7,macsr
; restore the macsr
Executing this sequence type can correctly save and restore the exact state of the EMAC programming
model.
5.3.1.3
MULS/MULU
MULS and MULU are unaffected by fractional-mode operation; operands remain assumed to be integers.
5.3.1.4
Scale Factor in MAC or MSAC Instructions
The scale factor is ignored while the MAC is in fractional mode.
5.3.2
EMAC Instruction Set Summary
summarizes EMAC unit instructions.
Table 5-8. EMAC Instruction Summary
Command
Mnemonic
Description
Multiply Signed
muls <ea>y,Dx
Multiplies two signed operands yielding a signed result
Multiply Unsigned
mulu <ea>y,Dx
Multiplies two unsigned operands yielding an unsigned result
Multiply Accumulate
mac Ry,RxSF,ACCx
msac Ry,RxSF,ACCx
Multiplies two operands and adds/subtracts the product
to/from an accumulator
Multiply Accumulate
with Load
mac Ry,Rx,<ea>y,Rw,ACCx
msac Ry,Rx,<ea>y,Rw,ACCx
Multiplies two operands and combines the product to an
accumulator while loading a register with the memory operand
Load Accumulator
move.l {Ry,#imm},ACCx
Loads an accumulator with a 32-bit operand
Store Accumulator
move.l ACCx,Rx
Writes the contents of an accumulator to a CPU register
Copy Accumulator
move.l ACCy,ACCx
Copies a 48-bit accumulator
Load MACSR
move.l {Ry,#imm},MACSR
Writes a value to MACSR
Store MACSR
move.l MACSR,Rx
Write the contents of MACSR to a CPU register
Store MACSR to CCR
move.l MACSR,CCR
Write the contents of MACSR to the CCR
Load MAC Mask Reg
move.l {Ry,#imm},MASK
Writes a value to the MASK register
Store MAC Mask Reg
move.l MASK,Rx
Writes the contents of the MASK to a CPU register
Load Accumulator
Extensions 01
move.l {Ry,#imm},ACCext01
Loads the accumulator 0,1 extension bytes with a 32-bit
operand
Summary of Contents for MCF54455
Page 33: ...xxviii Freescale Semiconductor ...
Page 67: ...Freescale Semiconductor 1 ...
Page 125: ...Freescale Semiconductor 1 ...
Page 145: ...Enhanced Multiply Accumulate Unit EMAC 5 21 Freescale Semiconductor ...
Page 173: ...Cache 6 28 Freescale Semiconductor ...
Page 179: ...Static RAM SRAM 7 6 Freescale Semiconductor ...
Page 207: ...Power Management 9 16 Freescale Semiconductor ...
Page 323: ...Reset Controller Module 13 8 Freescale Semiconductor ...
Page 389: ...Pin Multiplexing and Control 16 44 Freescale Semiconductor ...
Page 575: ...PCI Bus Controller 22 58 Freescale Semiconductor ...
Page 600: ...Advanced Technology Attachment ATA Freescale Semiconductor 23 25 ...
Page 601: ...Freescale Semiconductor 1 ...
Page 842: ...I2 C Interface Freescale Semiconductor 33 16 ...
Page 843: ...Freescale Semiconductor 1 ...
Page 921: ...Revision History A 6 Freescale Semiconductor ...