Integer Subtraction With Saturation to Result Size
SSUB
3-121
TMS320C62x/C67x Fixed-Point Instruction Set
Pipeline
Stage
E1
Read
src1, src2
Written
dst
Unit in use
.L
Instruction Type
Single-cycle
Delay Slots
0
Example 1
SSUB .L2
B1,B2,B3
Before instruction
1 cycle after instruction
2 cycles after instruction
B1
5A2E 51A3h
1512984995
B1
5A2E 51A3h
B1
5A2E 51A3h
B2
802A 3FA2h
–2144714846
B2
802A 3FA2h
B2
802A 3FA2h
B3
XXXX XXXXh
B3
7FFF FFFFh
2147483647
B3
7FFF FFFFh
CSR
0001 0100h
CSR
0001 0100h
CSR
0001 0300h
Saturated
Example 2
SSUB .L1
A0,A1,A2
Before instruction
1 cycle after instruction
2 cycles after instruction
A0
4367 71F2h
1130852850
A0
4367 71F2h
A0
4367 71F2h
A1
5A2E 51A3h
1512984995
A1
5A2E 51A3h
A1
5A2E 51A3h
A2
XXXX XXXXh
A2
E939 204Fh
–382132145
A2
E939 204Fh
CSR
0001 0100h
CSR
0001 0100h
CSR
0001 0100h
Not saturated
Pipeline