PIC18F2585_07 Datasheet, PDF (390/482 Pages) Microchip Technology – Enhanced Flash Microcontrollers with ECAN Technology, 10-Bit A/D and nanoWatt Technology

PIC18F2585/2680/4585/4680
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 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 0C4h
Before Instruction
W
PRODH
PRODL
= E2h
=?
=?
After Instruction
W
PRODH
PRODL
= E2h
= ADh
= 08h
MULWF
Syntax:
Operands:
Operation:
Status Affected:
Encoding:
Description:
Words:
Cycles:
Q Cycle Activity:
Q1
Decode
Multiply W with f
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 is
selected. If ‘a’ is ‘1’, the BSR is used
to select the GPR bank (default).
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.
1
1
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
DS39625C-page 388
Preliminary
© 2007 Microchip Technology Inc.