PIC18F258 Datasheet, PDF (319/384 Pages) Microchip Technology – High Performance, 28/40-Pin Enhanced FLASH Microcontrollers with CAN

PIC18FXX8
TSTFSZ
Test f, skip if 0
Syntax:
Operands:
Operation:
[ label ] TSTFSZ f [,a]
0 ≤ f ≤ 255
a ∈ [0,1]
skip if f = 0
Status Affected: None
Encoding:
Description:
Words:
Cycles:
0110 011a ffff ffff
If ’f’ = 0, the next instruction,
fetched during the current instruc-
tion execution is discarded and a
NOP is executed, making this a
two-cycle instruction. If ’a’ is 0, the
Access Bank will be selected, over-
riding the BSR value. If ’a’ is 1,
then the bank will be selected as
per the BSR value (default).
1
1(2)
Note: 3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ’f’
Process
Data
No
operation
If skip:
Q1
Q2
Q3
Q4
No
operation
No
operation
No
operation
No
operation
If skip and followed by 2-word instruction:
Q1
Q2
Q3
Q4
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
Example:
HERE TSTFSZ CNT
NZERO :
ZERO :
Before Instruction
PC
=
After Instruction
If CNT
=
PC
=
If CNT
≠
PC
=
Address (HERE)
0x00,
Address (ZERO)
0x00,
Address (NZERO)
XORLW
Exclusive OR literal with W
Syntax:
[ label ] XORLW k
Operands:
0 ≤ k ≤ 255
Operation:
(W) .XOR. k → W
Status Affected: N, Z
Encoding:
0000 1010 kkkk kkkk
Description:
The contents of W are XORed
with the 8-bit literal 'k'. The result
is placed in W.
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
literal ’k’
Process
Data
Write to W
Example:
XORLW 0xAF
Before Instruction
W
= 0xB5
After Instruction
W
= 0x1A
 2002 Microchip Technology Inc.
DS41159B-page 317