PIC16C621A Microchip Technology Inc., PIC16C621A Datasheet - Page 69

• Manufacturer Part Number: PIC16C621A
• Description: Eprom-based 8-bit Cmos Microcontrollers
• Manufacturer: Microchip Technology Inc.

DECFSZ
Syntax:
Operands:
Operation:
Status Affected:
Encoding:
Description:
Words:
Cycles:
Example
GOTO
Syntax:
Operands:
Operation:
Status Affected:
Encoding:
Description:
Words:
Cycles:
Example
 2003 Microchip Technology Inc.
Decrement f, Skip if 0
[ label ] DECFSZ f,d
0 ≤ f ≤ 127
d ∈ [0,1]
(f) - 1 → (dest);
None
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 instruc-
tion, which is already fetched, is
discarded. A NOP is executed
instead making it a two-cycle
instruction.
1
1(2)
Before Instruction
After Instruction
Unconditional Branch
[ label ]
0 ≤ k ≤ 2047
k → PC<10:0>
PCLATH<4:3> → PC<12:11>
None
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.
1
2
After Instruction
00
HERE
CONTINUE •
10
GOTO THERE
PC
CNT
if CNT =
PC
if CNT ≠
PC
PC =
GOTO k
=
=
=
=
1kkk
1011
DECFSZ
GOTO
•
•
address
CNT - 1
0,
address CONTINUE
0,
address HERE+1
Address THERE
skip if result = 0
dfff
kkkk
HERE
CNT, 1
LOOP
ffff
kkkk
INCF
Syntax:
Operands:
Operation:
Status Affected:
Encoding:
Description:
Words:
Cycles:
Example
Increment f
[ label ]
0 ≤ f ≤ 127
d ∈ [0,1]
(f) + 1 → (dest)
Z
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'.
1
1
Before Instruction
After Instruction
00
INCF
PIC16C62X
CNT
Z
CNT
Z
INCF f,d
1010
CNT,
1
DS30235J-page 67
=
=
=
=
dfff
0xFF
0
0x00
1
ffff