S3C80A5B
INSTRUCTION SET
6-87
XOR
—
Logical Exclusive OR
XOR
dst,src
Operation:
dst
←
dst XOR src
The source operand is logically exclusive-ORed with the destination operand and the result is stored
in the destination. The exclusive-OR operation results in a "1" bit being stored whenever the
corresponding bits in the operands are different; otherwise, a "0" bit is stored.
Flags:
C:
Unaffected.
Z:
Set if the result is "0"; cleared otherwise.
S:
Set if the result bit 7 is set; cleared otherwise.
V:
Always reset to "0".
D:
Unaffected.
H:
Unaffected.
Format:
Bytes
Cycles
Opcode
(Hex)
Addr Mode
dst src
opc
dst | src
2
4
B2
r
r
6
B3
r
lr
opc
src
dst
3
6
B4
R
R
6
B5
R
IR
opc
dst
src
3
6
B6
R
IM
Examples:
Given: R0 = 0C7H, R1 = 02H, R2 = 18H, register 00H = 2BH, register 01H = 02H, and
register 02H = 23H:
XOR
R0,R1
?
R0 = 0C5H, R1 = 02H
XOR
R0,@R1
?
R0 = 0E4H, R1 = 02H, register 02H = 23H
XOR
00H,01H
?
Register 00H = 29H, register 01H = 02H
XOR
00H,@01H
?
Register 00H = 08H, register 01H = 02H, register 02H = 23H
XOR
00H,#54H
?
Register 00H = 7FH
In the first example, if working register R0 contains the value 0C7H and if register R1 contains the
value 02H, the statement "XOR R0,R1" logically exclusive-ORs the R1 value with the R0 value and
stores the result (0C5H) in the destination register R0.