RFPIC12C509AG Datasheet, PDF (64/104 Pages) Microchip Technology – 18/20-Pin 8-Bit CMOS Microcontroller with UHF ASK/FSK Transmitter

rfPIC12C509AG/509AF
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 comple-
mented. 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 decre-
mented. 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
and an NOP is executed instead mak-
ing it a two cycle instruction.
Words:
1
Cycles:
1(2)
Example:
HERE
DECFSZ
GOTO
CONTINUE •
•
•
CNT, 1
LOOP
Before Instruction
PC
= address (HERE)
After Instruction
CNT =
if CNT =
PC
=
if CNT ≠
PC
=
CNT - 1;
0,
address (CONTINUE);
0,
address (HERE+1)
GOTO
Unconditional Branch
Syntax:
[ label ] GOTO k
Operands:
0 ≤ k ≤ 511
Operation:
k → PC<8:0>;
STATUS<6:5> → PC<10:9>
Status Affected: None
Encoding:
101k kkkk kkkk
Description:
GOTO is an unconditional branch. The
9-bit immediate value is loaded into PC
bits <8:0>. The upper bits of PC are
loaded from STATUS<6:5>. GOTO is a
two cycle instruction.
Words:
1
Cycles:
2
Example:
GOTO THERE
After Instruction
PC = address (THERE)
DS70031A-page 62
Preliminary
© 2001 Microchip Technology Inc.