PIC18F2450 MICROCHIP [Microchip Technology], PIC18F2450 Datasheet - Page 233

• Manufacturer Part Number: PIC18F2450
• Description: 28/40/44-Pin, High-Performance, 12 MIPS, Enhanced Flash, USB Microcontrollers with nanoWatt Technology
• Manufacturer: MICROCHIP [Microchip Technology]

DECFSZ
Syntax:
Operands:
Operation:
Status Affected:
Encoding:
Description:
Words:
Cycles:
Example:
© 2006 Microchip Technology Inc.
Q Cycle Activity:
If skip:
If skip and followed by 2-word instruction:
Before Instruction
After Instruction
operation
operation
operation
Decode
No
No
No
PC
CNT
If CNT
If CNT
Q1
Q1
Q1
PC =
PC =
=
=
=
register ‘f’
operation
operation
operation
Decrement f, Skip if 0
DECFSZ f {,d {,a}}
0
d
a
(f) – 1
skip if result = 0
None
The contents of register ‘f’ are
decremented. If ‘d’ is ‘0’, the result is
placed in W. If ‘d’ is ‘1’, the result is
placed back in register ‘f’ (default).
If the result is ‘0’, the next instruction,
which is already fetched, is discarded
and a NOP is executed instead, making
it a two-cycle instruction.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f
Section 19.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
1
1(2)
Note: 3 cycles if skip and followed
HERE
CONTINUE
Read
No
No
No
0010
Q2
Q2
Q2
Address (HERE)
CNT – 1
0;
Address (CONTINUE)
0;
Address (HERE + 2)
f
[0,1]
[0,1]
255
by a 2-word instruction.
dest,
11da
operation
operation
operation
GOTO
DECFSZ
Process
Data
No
No
No
Q3
Q3
Q3
95 (5Fh). See
ffff
CNT, 1, 1
LOOP
destination
operation
operation
operation
Advance Information
Write to
No
No
No
Q4
Q4
Q4
ffff
DCFSNZ
Syntax:
Operands:
Operation:
Status Affected:
Encoding:
Description:
Words:
Cycles:
Example:
Q Cycle Activity:
If skip:
If skip and followed by 2-word instruction:
Before Instruction
After Instruction
operation
operation
operation
Decode
No
No
No
TEMP
TEMP
If TEMP
If TEMP
PIC18F2450/4450
Q1
Q1
Q1
PC
PC
register ‘f’
operation
operation
operation
Decrement f, Skip if Not 0
DCFSNZ
0
d
a
(f) – 1
skip if result
None
The contents of register ‘f’ are
decremented. If ‘d’ is ‘0’, the result is
placed in W. If ‘d’ is ‘1’, the result is
placed back in register ‘f’ (default).
If the result is not ‘0’, the next
instruction, which is already fetched, is
discarded and a NOP is executed
instead, making it a two-cycle
instruction.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f
Section 19.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
1
1(2)
Note:
HERE
ZERO
NZERO
Read
0100
No
No
No
Q2
Q2
Q2
f
[0,1]
[0,1]
255
=
=
=
=
=
3 cycles if skip and followed
by a 2-word instruction.
dest,
DCFSNZ
:
:
f {,d {,a}}
11da
operation
operation
operation
?
TEMP – 1,
0;
Address (ZERO)
0;
Address (NZERO)
Process
0
Data
No
No
No
Q3
Q3
Q3
DS39760A-page 231
95 (5Fh). See
ffff
TEMP, 1, 0
destination
operation
operation
operation
Write to
No
No
No
Q4
Q4
Q4
ffff