
PIC16F8X
DS30430C-page 60
1998 Microchip Technology Inc.
CLRF
Clear f
Syntax:
[
label] CLRF
f
Operands:
0
≤ f ≤ 127
Operation:
00h
→ (f)
1
→ Z
Status Affected:
Z
Encoding:
00
0001
1fff
ffff
Description:
The contents of register ’f’ are cleared
and the Z bit is set.
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register
’f’
Process
data
Write
register ’f’
Example
CLRF
FLAG_REG
Before Instruction
FLAG_REG
=
0x5A
After Instruction
FLAG_REG
=
0x00
Z=
1
CLRW
Clear W
Syntax:
[
label ] CLRW
Operands:
None
Operation:
00h
→ (W)
1
→ Z
Status Affected:
Z
Encoding:
00
0001
0xxx
xxxx
Description:
W register is cleared. Zero bit (Z) is
set.
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
No-Opera
tion
Process
data
Write to
W
Example
CLRW
Before Instruction
W
=
0x5A
After Instruction
W
=
0x00
Z=
1
CLRWDT
Clear Watchdog Timer
Syntax:
[
label ] CLRWDT
Operands:
None
Operation:
00h
→ WDT
0
→ WDT prescaler,
1
→ TO
1
→ PD
Status Affected:
TO, PD
Encoding:
00
0000
0110
0100
Description:
CLRWDT
instruction resets the Watch-
dog Timer. It also resets the prescaler
of the WDT. Status bits TO and PD are
set.
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
No-Opera
tion
Process
data
Clear
WDT
Counter
Example
CLRWDT
Before Instruction
WDT counter =
?
After Instruction
WDT counter =
0x00
WDT prescaler=
0
TO
=1
PD
=1