PIC18LF2431-I/ML View Datasheet(PDF) - Microchip Technology

Part Name

Description

Manufacturer

PIC18LF2431-I/ML

28/40/44-Pin Enhanced Flash Microcontrollers with nanoWatt Technology, High-Performance PWM and A/D

Microchip Technology 

PIC18F2331/2431/4331/4431

SUBWFB

Syntax:

Operands:

Operation:

Status Affected:

Encoding:

Description:

Words:

Cycles:

Q Cycle Activity:

Q1

Decode

Subtract W from f with Borrow

[ label ] SUBWFB f [,d [,a]]

0  f  255

d  [0,1]

a  [0,1]

(f) – (W) – (C) dest

N, OV, C, DC, Z

0101 10da ffff ffff

Subtract W and the Carry flag (borrow)

from register, ‘f’ (2’s complement

method). If ‘d’ is ‘0’, the result is stored in

W. If ‘d’ is ‘1’, the result is stored back in

register, ‘f’. If ‘a’ is ‘0’, the Access Bank

will be selected, overriding the BSR

value. If ‘a’ is ‘1’, then the bank will be

selected as per the BSR value.

1

1

Q2

Read

register ‘f’

Q3

Process

Data

Q4

Write to

destination

Example 1:

SUBWFB REG, 1, 0

Before Instruction

REG =

W

=

C

=

After Instruction

REG =

W

=

C

=

Z

=

N

=

0x19

0x0D

0x01

0x0C

0x0D

0x01

0x00

0x00

(0001 1001)

(0000 1101)

(0000 1011)

(0000 1101)

; result is positive

Example 2:

SUBWFB REG, 0, 0

Before Instruction

REG =

W

=

C

=

After Instruction

REG =

W

=

C

=

Z

=

N

=

0x1B

0x1A

0x00

0x1B

0x00

0x01

0x01

0x00

(0001 1011)

(0001 1010)

(0001 1011)

; result is zero

Example 3:

SUBWFB REG, 1, 0

Before Instruction

REG =

W

=

C

=

After Instruction

REG =

0x03

0x0E

0x01

0xF5

W

= 0x0E

C

= 0x00

Z

= 0x00

N

= 0x01

(0000 0011)

(0000 1101)

(1111 0100)

; [2’s comp]

(0000 1101)

; result is negative

SWAPF

Syntax:

Operands:

Operation:

Status Affected:

Encoding:

Description:

Words:

Cycles:

Q Cycle Activity:

Q1

Decode

Swap f

[ label ] SWAPF f [,d [,a]]

0  f  255

d  [0,1]

a  [0,1]

(f<3:0>)  dest<7:4>,

(f<7:4>)  dest<3:0>

None

0011 10da ffff ffff

The upper and lower nibbles of register,

‘f’, are exchanged. If ‘d’ is ‘0’, the result

is placed in W. If ‘d’ is ‘1’, the result is

placed in register, ‘f’. If ‘a’ is ‘0’, the

Access Bank will be selected, overrid-

ing the BSR value. If ‘a’ is ‘1’, then the

bank will be selected as per the BSR

value.

1

1

Q2

Read

register ‘f’

Q3

Process

Data

Q4

Write to

destination

Example:

SWAPF REG

Before Instruction

REG = 0x53

After Instruction

REG = 0x35

DS39616D-page 320

 2010 Microchip Technology Inc.

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