PIC18F2331 Datasheet, PDF (330/396 Pages) Microchip Technology – 28/40/44-Pin Enhanced Flash Microcontrollers with nanoWatt Technology, High Performance PWM and A/D

PIC18F2331/2431/4331/4431
TSTFSZ
Test f, skip if 0
Syntax:
[ label ] TSTFSZ f [,a]
Operands:
0 ≤ f ≤ 255
a ∈ [0,1]
Operation:
skip if f = 0
Status Affected: None
Encoding:
0110 011a ffff ffff
Description:
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).
Words:
1
Cycles:
1(2)
Note: 3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1
Q2
Decode
Read
register ‘f’
If skip:
Q3
Process
Data
Q4
No
operation
Q1
Q2
Q3
Q4
No
operation
No
operation
No
operation
No
operation
If skip and followed by 2-word instruction:
Q1
No
operation
No
operation
Q2
No
operation
No
operation
Q3
No
operation
No
operation
Q4
No
operation
No
operation
Example:
HERE TSTFSZ CNT
NZERO :
ZERO :
Before Instruction
PC = Address (HERE)
After Instruction
If CNT
PC
If CNT
PC
= 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
Decode
Q2
Read
literal ‘k’
Q3
Process
Data
Q4
Write to W
Example:
XORLW 0xAF
Before Instruction
W
= 0xB5
After Instruction
W
= 0x1A
DS39616B-page 328
Preliminary
 2003 Microchip Technology Inc.