PIC18F2455T-I/ML View Datasheet(PDF) - Microchip Technology

Part Name

Description

Manufacturer

PIC18F2455T-I/ML

28/40/44-Pin, High-Performance, Enhanced Flash, USB Microcontrollers with nanoWatt Technology

Microchip Technology 

PIC18F2455/2550/4455/4550

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

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 26.2.3

“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

DS39632E-page 340

© 2009 Microchip Technology Inc.

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