PIC18FXX39 Datasheet, PDF (238/322 Pages) Microchip Technology – Enhanced FLASH Microcontrollers with Single Phase Induction Motor Control Kernel

PIC18FXX39
MULLW
Multiply Literal with W
Syntax:
[ label ] MULLW k
Operands:
0  k  255
Operation:
(W) x k  PRODH:PRODL
Status Affected: None
Encoding:
0000 1101 kkkk kkkk
Description:
An unsigned multiplication is car-
ried out between the contents of
W and the 8-bit literal 'k'. The
16-bit result is placed in
PRODH:PRODL register pair.
PRODH contains the high byte.
W is unchanged.
None of the status flags are
affected.
Note that neither overflow nor
carry is possible in this opera-
tion. A zero result is possible but
not detected.
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
literal 'k'
Process
Data
Write
registers
PRODH:
PRODL
Example:
MULLW 0xC4
Before Instruction
W
=
PRODH
=
PRODL
=
After Instruction
0xE2
?
?
W
PRODH
PRODL
= 0xE2
= 0xAD
= 0x08
MULWF
Multiply W with f
Syntax:
Operands:
Operation:
Status Affected:
Encoding:
Description:
[ label ] MULWF f [,a]
0  f  255
a  [0,1]
(W) x (f)  PRODH:PRODL
None
0000 001a ffff ffff
An unsigned multiplication is car-
ried out between the contents of
W and the register file location 'f'.
The 16-bit result is stored in the
PRODH:PRODL register pair.
PRODH contains the high byte.
Both W and 'f' are unchanged.
None of the status flags are
affected.
Note that neither overflow nor
carry is possible in this opera-
tion. A zero result is possible but
not detected. 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
registers
PRODH:
PRODL
Example:
MULWF REG, 1
Before Instruction
W
=
REG
=
PRODH
=
PRODL
=
After Instruction
0xC4
0xB5
?
?
W
REG
PRODH
PRODL
= 0xC4
= 0xB5
= 0x8A
= 0x94
DS30485B-page 238
Preliminary
 2002-2013 Microchip Technology Inc.