DSP Core Reference Manual

IMPY
SC140 DSP Core Reference Manual A-187
IMPY Integer Multiply (DALU) IMPY
Description
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Example
impy d3,d4,d0
514 $0202
x –2
$FFFE
–1028 $FBFC
Instruction Formats and Opcodes
Note: ** indicates serial grouping encoding.
Operation Assembler Syntax
Da.L * Db.L → Dn
IMPY Da,Db,Dn
IMPY Da,Db,Dn
Performs a signed integer multiplication on the low portions of two signed source data registers (Da, Db)
and stores the product in a destination data register (Dn).
Register Address Bit Name Description
Ln L Clears the Ln bit in the destination register.
Register/Memory Address Before After
D3
$FF FFFF 0202
D4
$00 0000 FFFE
L0:D0
$0:$FF FFFF FBFC
Instruction Words Cycles Type Opcode
15 8 7 0
IMPY Da,Da,Dn 1 1 1 0*1010FFF11101 j j
15 8 7 0
IMPY Da,Db,Dn 1 1 1 0*1010FFF01JJJJJ