Semiconductor Group
4-79
1998-04-01
Instruction Set
C500 Family
XRL
<dest-byte>, <src-byte>
Function:
Logical Exclusive OR for byte variables
Description:
XRL performs the bitwise logical Exclusive OR operation between the indicated
variables, storing the results in the destination. No flags are affected (except P, if
<dest-byte> = A).
The two operands allow six addressing mode combinations. When the destination
is the accumulator, the source can use register, direct, register-indirect, or
immediate addressing; when the destination is a direct address, the source can be
accumulator or immediate data.
Note:
When this instruction is used to modify an output port, the value used as the original
port data will be read from the output data latch,
not
the input pins.
Example:
If the accumulator holds 0C3H (11000011B) and register 0 holds 0AAH
(10101010B) then the instruction
XRL
A,R0
will leave the accumulator holding the value 69H (01101001B).
When the destination is a directly addressed byte, this instruction can complement
combinations of bits in any RAM location or hardware register. The pattern of bits
to be complemented is then determined by a mask byte, either a constant contained
in the instruction or a variable computed in the accumulator at run-time. The
instruction
XRL
P1,#00110001B
will complement bits 5, 4, and 0 of output port 1.
XRL
A,Rn
Operation:
XRL2
(A)
¬
(A) (Rn)
Bytes:
1
Cycles:
1
Encoding:
0 1 1 0
1 r r r
v