Datasheet

 1996-2013 Microchip Technology Inc. Preliminary DS40143E-page 59
PIC16C55X
DECFSZ Decrement f, Skip if 0
Syntax: [ label ] DECFSZ f,d
Operands: 0  f  127
d  [0,1]
Operation: (f) - 1  (dest); skip if result = 0
Status Affected: None
Encoding:
00 1011 dfff ffff
Description:
The contents of register 'f' are
decremented. 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 instruction,
which is already fetched, is discarded.
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
GOTO Unconditional Branch
Syntax: [ label ] GOTO k
Operands: 0  k  2047
Operation: k  PC<10:0>
PCLATH<4:3>  PC<12:11>
Status Affected: None
Encoding:
10 1kkk kkkk kkkk
Description:
GOTO is an unconditional branch. The
eleven bit immediate value is loaded
into PC bits <10:0>. The upper bits of
PC are loaded from PCLATH<4:3>.
GOTO is a two-cycle instruction.
Words: 1
Cycles: 2
Example
GOTO THERE
After Instruction
PC = Address THERE
INCF Increment f
Syntax: [ label ] INCF f,d
Operands: 0  f  127
d  [0,1]
Operation: (f) + 1  (dest)
Status Affected: Z
Encoding:
00 1010 dfff ffff
Description:
The contents of register 'f' are
incremented. If 'd' is 0 the result is
placed in the W register. If 'd' is 1 the
result is placed back in register 'f'.
Words: 1
Cycles: 1
Example
INCF CNT, 1
Before Instruction
CNT = 0xFF
Z=0
After Instruction
CNT = 0x00
Z=1