80 subb subtract byte – Texas Instruments MSP50C614 User Manual
Page 268
Individual Instruction Descriptions
4-176
4.14.80
SUBB
Subtract Byte
Syntax
[label]
name
dest, src
Clock,
clk
Word,
w
With RPT,
clk
Class
SUBB
A
n, imm8
1
1
N/R
2a
SUBB
R
x, imm8
1
1
N/R
4b
Execution
dest
⇐
dest – imm8
PC
⇐
PC + 1
Flags Affected
dest is An:
OF, SF, ZF, CF are set accordingly
dest is Rx:
RCF, RZF are set accordingly
Opcode
Instructions
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
SUBB A
n imm8
1
0
1
0
0
1
0
A
n
imm8
SUBB R
x, imm8
1
0
1
1
0
1
k4
k3
k2
k7
k6
k5
R
x
k1
k0
Description
Subtract value of
src byte from value of dest byte and store result in dest. Note
that subtraction is performed in 2’s complement and therefore the CF (carry
flag) may get set even when subtracting a smaller value from a larger value.
Syntax
Description
SUBB A
n, imm8
Subtract immediate byte from A
n
SUBB R
x, imm8
Subtract immediate byte from R
x
Example 4.14.80.1
SUBB A2, 0x45
Subtract 0x45 from accumulator A2 byte.
Example 4.14.80.2
SUBB R3, 0xF2
Subtract 0xF2 from register R3 byte.