PIC17C4X
CLRWDT
Syntax:
Clear Watchdog Timer
COMF
Complement f
[ label ] COMF f,d
0 ≤ f ≤ 255
[ label ] CLRWDT
None
Syntax:
Operands:
Operands:
Operation:
d
[0,1]
00h → WDT
0 → WDT postscaler,
1 → TO
Operation:
(f) → (dest)
Status Affected:
Encoding:
Z
1 → PD
0001
001d
ffff
ffff
Status Affected:
Encoding:
TO, PD
The contents of register 'f' are comple-
mented. If 'd' is 0 the result is stored in
WREG. If 'd' is 1 the result is stored
back in register 'f'.
Description:
0000
0000
0000
0100
CLRWDTinstruction resets the watchdog
timer. It also resets the prescaler of the
WDT. Status bits TO and PD are set.
Description:
Words:
Cycles:
1
1
Words:
Cycles:
1
1
Q Cycle Activity:
Q1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Q2
Q3
Q4
Decode
Read
Execute
Write
register 'f'
register 'f'
Decode
Read
Execute
NOP
register
ALUSTA
COMF
REG1,0
Example:
Before Instruction
CLRWDT
Example:
REG1
=
0x13
Before Instruction
After Instruction
WDT counter
=
?
REG1
=
0x13
WREG
=
0xEC
After Instruction
WDT counter
WDT Postscaler
TO
=
=
=
=
0x00
0
1
1
PD
DS30412C-page 118
1996 Microchip Technology Inc.
MICROCHIP [ MICROCHIP ]
