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PIC17C7XX Datasheet, PDF (217/328 Pages) Microchip Technology – High-Performance 8-Bit CMOS EPROM Microcontrollers with 10-bit A/D | |||
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MULLW
Syntax:
Operands:
Operation:
Status Affected:
Encoding:
Description:
Words:
Cycles:
Q Cycle Activity:
Q1
Decode
Multiply Literal with WREG
[ label ] MULLW k
0 ⤠k ⤠255
(k x WREG) â PRODH:PRODL
None
1011 1100 kkkk kkkk
An unsigned multiplication is carried
out between the contents of WREG
and the 8-bit literal 'k'. The 16-bit
result is placed in PRODH:PRODL
register pair. PRODH contains the
high byte.
WREG is unchanged.
None of the status ï¬ags are affected.
Note that neither overï¬ow 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
WREG
=
PRODH
=
PRODL
=
0xE2
?
?
After Instruction
WREG
=
PRODH
=
PRODL
=
0xC4
0xAD
0x08
PIC17C7XX
MULWF
Multiply WREG with f
Syntax:
[ label ] MULWF f
Operands:
0 ⤠f ⤠255
Operation:
(WREG x f) â PRODH:PRODL
Status Affected: None
Encoding:
0011 0100 ffff ffff
Description:
An unsigned multiplication is carried
out between the contents of WREG
and the register ï¬le location 'f'. The
16-bit result is stored in the
PRODH:PRODL register pair.
PRODH contains the high byte.
Both WREG and 'f' are unchanged.
None of the status ï¬ags are affected.
Note that neither overï¬ow nor carry
is possible in this operation. A zero
result is possible but not detected.
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Decode
Q2
Read
register 'f'
Q3
Process
Data
Q4
Write
registers
PRODH:
PRODL
Example:
MULWF REG
Before Instruction
WREG
=
REG
=
PRODH
=
PRODL
=
0xC4
0xB5
?
?
After Instruction
WREG
=
REG
=
PRODH
=
PRODL
=
0xC4
0xB5
0x8A
0x94
© 1998 Microchip Technology Inc.
DS30289A-page 217
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