PIC18F4539 Datasheet, PDF (232/322 Pages) Microchip Technology – Enhanced FLASH Microcontrollers with Single Phase Induction Motor Control Kernel

PIC18FXX39
DAW
Syntax:
Operands:
Operation:
Decimal Adjust W Register
[ label ] DAW
None
If [W<3:0> >9] or [DC = 1] then
(W<3:0>) + 6 → W<3:0>;
else
(W<3:0>) → W<3:0>;
If [W<7:4> >9] or [C = 1] then
(W<7:4>) + 6 → W<7:4>;
else
(W<7:4>) → W<7:4>;
Status Affected: C
Encoding:
0000 0000 0000 0111
Description:
DAW adjusts the eight-bit value in
W, resulting from the earlier addi-
tion of two variables (each in
packed BCD format) and produces
a correct packed BCD result.
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register W
Process
Data
Write
W
Example1:
DAW
Before Instruction
W
=
C
=
DC
=
After Instruction
0xA5
0
0
W
C
DC
Example 2:
= 0x05
=1
=0
Before Instruction
W
=
C
=
DC
=
After Instruction
0xCE
0
0
W
= 0x34
C
=1
DC
=0
DECF
Decrement f
Syntax:
[ label ] DECF f [,d [,a]
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operation:
(f) – 1 → dest
Status Affected: C, DC, N, OV, Z
Encoding:
0000 01da ffff ffff
Description:
Decrement register 'f'. If 'd' is 0, the
result is stored in W. If 'd' is 1, the
result is stored back in register 'f'
(default). If ‘a’ is 0, the Access
Bank will be selected, overriding
the BSR value. If ‘a’ = 1, then the
bank will be selected as per the
BSR value (default).
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Q2
Decode
Read
register 'f'
Q3
Process
Data
Q4
Write to
destination
Example:
DECF CNT,
Before Instruction
CNT
Z
= 0x01
=0
After Instruction
CNT
Z
= 0x00
=1
1, 0
DS30485A-page 230
Preliminary
 2002 Microchip Technology Inc.