Example 2, Instruction formats and opcodes, Instruction fields – Freescale Semiconductor StarCore SC140 User Manual
Page 634: Mpy d6,d6,d7
A-320
SC140 DSP Core Reference Manual
MPY
0.010
$2000 1/4
x 1.100$C000 –1/2
1.111
$F000 –1/8
Example 2
mpy d6,d6,d7
Instruction Formats and Opcodes
Note:
** indicates serial grouping encoding.
Instruction Fields
Da,Da
jj
Data Register Pairs
Da,Db
JJJJJ
Data Register Pairs
Register/Memory Address
Before
After
D6
$FF C000 0000
L7:D7
$0:$00 2000 0000
Instruction
Words Cycles Type
Opcode
15
8
7
0
MPY Da,Da,Dn
1
1
1
0
*
1
0
1
0
F
F
F
1
1
1
0
0
j
j
15
8
7
0
MPY Da,Db,Dn
1
1
1
0
*
1
0
0
0
F
F
F
0
1
J
J
J
J
J
00
D1,D1
01
D3,D3
10
D5,D5
11
D7,D7
Note:
This instruction can specify D8-D15 as operands by using a prefix.
00000
D0,D4
01000
D2,D4
10000
D0,D0
11000
D1,D2
00001
D0,D5
01001
D2,D5
10001
D0,D1
11001
D1,D3
00010
D0,D6
01010
D2,D6
10010
D0,D2
11010
D5,D6
00011
D0,D7
01011
D2,D7
10011
D0,D3
11011
D5,D7
00100
D1,D4
01100
D3,D4
10100
D4,D4
11100
D2,D2
00101
D1,D5
01101
D3,D5
10101
D4,D5
11101
D2,D3
00110
D1,D6
01110
D3,D6
10110
D4,D6
11110
D6,D6
00111
D1,D7
01111
D3,D7
10111
D4,D7
11111
D6,D7
Notes:
1.
This instruction can specify D8-D15 as operands by using a prefix.
2.
Register pair order can be inverted for clarity because the order of operation is not important
for multiply operations.
3.
The JJJJJ encoding does not include the pairs: D1–D1, D3–D3, D5–D5, and D7–D7. These
are covered in the jj encoding.