Signed or Unsigned Integer Subtraction Without Saturation
SUB(U)
3-129
TMS320C62x/C67x Fixed-Point Instruction Set
Opcode map field used...
Mnemonic
Opfield
Unit
For operand type...
src2
src1
dst
sint
sint
sint
.D1, .D2
010001
SUB
src2
src1
dst
sint
ucst
5
sint
.D1, .D2
010011
SUB
Opcode
.L unit form:
31
29 28 27
23 22
18 17
creg
z
dst
13 12 11
5
4
3
2
1
0
x
op
1
1
0
s
p
3
5
5
5
7
src2
src1/cst
.S unit form:
31
29 28 27
23 22
18 17
creg
z
dst
13 12
5
4
3
2
1
0
op
0
0
0
s
p
3
5
5
5
6
6
1
11
x
src1/cst
src2
Description for .L1, .L2 and .S1, .S2 Opcodes
src2 is subtracted from src1. The result is placed in dst.
Execution for .L1, .L2 and .S1, .S2 Opcodes
if (cond)
src1 – src2
→
dst
else
nop
Opcode
.D unit form:
31
29 28 27
23 22
18 17
creg
z
dst
13 12
5
4
3
2
1
0
op
0
0
0
s
p
3
5
5
5
6
7
6
1
0
src2
src1/cst
Description for .D1, .D2 Opcodes
src1 is subtracted from src2. The result is placed in dst.
Execution for .D1, .D2 Opcodes
if (cond)
src2 – src1
→
dst
else
nop