PIC18F67J11-IPT Datasheet, PDF (358/448 Pages) Microchip Technology – 64/80-Pin High-Performance, 1-Mbit Flash Microcontrollers with nanoWatt Technology

PIC18F87J11 FAMILY
MULLW
Syntax:
Operands:
Operation:
Status Affected:
Encoding:
Description:
Words:
Cycles:
Q Cycle Activity:
Q1
Decode
Multiply Literal with W
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 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 0C4h
Before Instruction
W
PRODH
PRODL
= E2h
=?
=?
After Instruction
W
PRODH
PRODL
= E2h
= ADh
= 08h
MULWF
Multiply W with f
Syntax:
Operands:
Operation:
Status Affected:
MULWF f {,a}
0 ≤ f ≤ 255
a ∈ [0,1]
(W) x (f) → PRODH:PRODL
None
Encoding:
Description:
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 is selected. If
‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction set
is enabled, this instruction operates in
Indexed Literal Offset Addressing mode
whenever f ≤ 95 (5Fh). See
Section 25.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Decode
Q2
Read
register ‘f’
Q3
Process
Data
Q4
Write
registers
PRODH:
PRODL
Example:
MULWF REG, 1
Before Instruction
W
REG
PRODH
PRODL
= C4h
= B5h
=?
=?
After Instruction
W
REG
PRODH
PRODL
= C4h
= B5h
= 8Ah
= 94h
DS39778D-page 358
© 2009 Microchip Technology Inc.