PIC18LF45J50-I/ML301 View Datasheet(PDF) - Microchip Technology

Part Name

Description

Manufacturer

PIC18LF45J50-I/ML301

28/44-Pin, Low-Power, High-Performance USB Microcontrollers with nanoWatt XLP Technology

Microchip Technology 

PIC18F46J50 FAMILY

SUBFSR

Syntax:

Operands:

Operation:

Status Affected:

Encoding:

Description:

Words:

Cycles:

Q Cycle Activity:

Q1

Decode

Subtract Literal from FSR

SUBFSR f, k

0  k  63

f  [ 0, 1, 2 ]

FSRf – k  FSRf

None

1110 1001 ffkk kkkk

The 6-bit literal, ‘k’, is subtracted

from the contents of the FSR

specified

by ‘f’.

1

1

Q2

Read

register ‘f’

Q3

Process

Data

Q4

Write to

destination

Example:

SUBFSR 2, 0x23

Before Instruction

FSR2 = 03FFh

After Instruction

FSR2 = 03DCh

SUBULNK

Subtract Literal from FSR2 and Return

Syntax:

Operands:

Operation:

Status Affected:

Encoding:

SUBULNK k

0  k  63

FSR2 – k  FSR2,

(TOS) PC

None

1110 1001

11kk

kkkk

Description:

The 6-bit literal, ‘k’, is subtracted from

the contents of the FSR2. A RETURN is

then executed by loading the PC with

the TOS.

The instruction takes two cycles to

execute; a NOP is performed during the

second cycle.

This may be thought of as a special case

of the SUBFSR instruction, where f = 3

(binary ‘11’); it operates only on FSR2.

Words:

1

Cycles:

2

Q Cycle Activity:

Q1

Q2

Q3

Q4

Decode

Read

register ‘f’

Process

Data

Write to

destination

No

Operation

No

Operation

No

Operation

No

Operation

Example:

SUBULNK 0x23

Before Instruction

FSR2 = 03FFh

PC

= 0100h

After Instruction

FSR2 =

PC

=

03DCh

(TOS)

 2011 Microchip Technology Inc.

DS39931D-page 481

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