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6.0 Instruction Set Reference (Continued)
XOR
Exclusive OR Immediate
Syntax
XOR n, rsd -immediate, limited register
Affected Flags
N,Z
Description
Logically exclusive ORs the immediate value n to the register
rsd and places the result back into the register rsd. Note
that only the active registers RO-R15 may be specified for
rsd. The value of n is 8 bits wide.
Example
Encode/decode a data byte in register 20.
XOR code-pattern, R20 ;encode/decode
Instruction Format
1 0 11 1 1 1 0 I
. Opcode .
15 11
T-states
2
Bus Timing
Figure 7
Operation
rsd XOR n -
rsd
n
rsd
3 0
XORA Exclusive OR with Accumulator
Syntax
XORA Rs, Rd
XORA Rs, [mlr]
-register, register
-register, indexed
Affected Flags
N,Z
Description
Logically exclusive ORs the source register Rs to the active
accumulator and places the result into the destination specified.
The destination may be either a register, Rd, or data
memory via an index register mode, [mlr]. Note that register
bank selection determines which accumulator is active.
Example
Decode the data byte just received and place it into data
memory. This example assumes that the accumulator contains
the "key" and that the index register IY points to the
location where the information should be stored.
EXX 1,1 ;select alternate banks
XORA
Instruction Format
XORA Rs, Rd
RTR, [IY + ] ;decode received byte and
; save it
15 9
XORA Rs, [Mlr]
1
Rd
15 8 6 4
T-states
XORA Rs, Rd -2
XORA Rs, [mlr] -3
00 - post-decrement
01 - no change
10 - post Increment
11 - pre-Increment
Bus Timing
XORA Rs, Rd -Figure 7
XORA Rs, [mlr] -Figure 12
Operation
XORA Rs, Rd
Rs XOR accumulator -
XORA Rs, [mlr]
Rs XOR accumulator -
Rd
data memory
4
1 1
Rs
i i
R.
~
00 -IW
01 - IX
10 - IY
11 - IZ
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TL/F/9336-16
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