Datasheet

PIC16C5X
DS30453E-page 54 Preliminary  1997-2013 Microchip Technology Inc.
COMF Complement f
Syntax: [ label ] COMF f,d
Operands: 0  f  31
d  [0,1]
Operation: (f
)  (dest)
Status Affected: Z
Encoding: 0010 01df ffff
Description: The contents of register 'f' are
complemented. If 'd' is 0 the result
is stored in the W register. If 'd' is 1
the result is stored back in
register 'f'.
Words: 1
Cycles: 1
Example: COMF REG1,0
Before Instruction
REG1 = 0x13
After Instruction
REG1 = 0x13
W=0xEC
DECF Decrement f
Syntax: [ label ] DECF f,d
Operands: 0  f  31
d  [0,1]
Operation: (f) – 1  (dest)
Status Affected: Z
Encoding: 0000 11df ffff
Description: Decrement register 'f'. If 'd' is 0 the
result is stored in the W register. If
'd' is 1 the result is stored back in
register 'f'.
Words: 1
Cycles: 1
Example: DECF CNT, 1
Before Instruction
CNT = 0x01
Z=0
After Instruction
CNT = 0x00
Z=1
DECFSZ Decrement f, Skip if 0
Syntax: [ label ] DECFSZ f,d
Operands: 0  f  31
d  [0,1]
Operation: (f) – 1  d; skip if result = 0
Status Affected: None
Encoding: 0010 11df ffff
Description: The contents of register 'f' are dec-
remented. If 'd' is 0 the result is
placed in the W register. If 'd' is 1
the result is placed back in
register 'f'.
If the result is 0, the next instruc-
tion, which is already fetched, is
discarded and a NOP is executed
instead making it a two-cycle
instruction.
Words: 1
Cycles: 1(2)
Example: HERE DECFSZ CNT, 1
GOTO LOOP
CONTINUE •
•
•
Before Instruction
PC = address(HERE)
After Instruction
CNT = CNT - 1;
if CNT = 0,
PC = address (CONTINUE);
if CNT  0,
PC = address (HERE+1)