PIC18FXX8 Datasheet, PDF (310/402 Pages) Microchip Technology – 28/40-Pin High-Performance, Enhanced Flash Microcontrollers with CAN Module

PIC18FXX8
MULLW
Syntax:
Operands:
Operation:
Status Affected:
Encoding:
Description:
Words:
Cycles:
Q Cycle Activity:
Q1
Decode
Multiply Literal with W
[ label ] MULLW k
0 ≤ k ≤ 255
(W) x k → PRODH:PRODL
None
0000 1101 kkkk kkkk
An unsigned multiplication is carried out
between the contents of W and the 8-bit
literal ‘k’. The 16-bit result is placed in
the 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 operation. A Zero result
is possible but not detected.
1
1
Q2
Read
literal ‘k’
Q3
Process
Data
Q4
Write
registers
PRODH:
PRODL
Example:
MULLW 0xC4
Before Instruction
W
=
PRODH
=
PRODL
=
After Instruction
W
=
PRODH
=
PRODL
=
0xE2
?
?
0xE2
0xAD
0x08
MULWF
Syntax:
Operands:
Operation:
Status Affected:
Encoding:
Description:
Words:
Cycles:
Q Cycle Activity:
Q1
Decode
Multiply W with f
[ label ] MULWF f [,a]
0 ≤ f ≤ 255
a ∈ [0,1]
(W) x (f) → PRODH:PRODL
None
0000 001a ffff ffff
An unsigned multiplication is carried 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 operation. 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).
1
1
Q2
Read
register ‘f’
Q3
Process
Data
Q4
Write
registers
PRODH:
PRODL
Example:
MULWF REG
Before Instruction
W
=
REG
=
PRODH
=
PRODL
=
After Instruction
W
=
REG
=
PRODH
=
PRODL
=
0xC4
0xB5
?
?
0xC4
0xB5
0x8A
0x94
DS41159D-page 308
 2004 Microchip Technology Inc.