Impy, Integer multiply (dalu), Instruction formats and opcodes – Freescale Semiconductor StarCore SC140 User Manual
Page 501: Operation assembler syntax, Impy d3,d4,d0
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
*
1
0
1
0
F
F
F
1
1
1
0
1
j
j
15
8
7
0
IMPY Da,Db,Dn
1
1
1
0
*
1
0
1
0
F
F
F
0
1
J
J
J
J
J