PIC16LC925T-I/CL View Datasheet(PDF) - Microchip Technology

Part Name

Description

Manufacturer

PIC16LC925T-I/CL

64/68-Pin CMOS Microcontrollers with LCD Driver

Microchip Technology 

PIC16C925/926

RETFIE

Return from Interrupt

Syntax:

Operands:

Operation:

Status Affected:

[ label ] RETFIE

None

TOS → PC,

1 → GIE

None

Encoding:

00

0000 0000 1001

Description:

Words:

Cycles:

Return from Interrupt. Stack is POPed

and Top-of-Stack (TOS) is loaded in

the PC. Interrupts are enabled by set-

ting Global Interrupt Enable bit, GIE

(INTCON<7>). This is a two-cycle

instruction.

1

2

Q Cycle Activity:

Q1

Q2

Q3

Q4

1st Cycle Decode No Set the Pop from

Operation GIE bit the Stack

2nd Cycle No

No

No

No

Operation Operation Operation Operation

Example

RETFIE

After Interrupt:

PC = TOS

GIE = 1

RETLW

Return with Literal in W

Syntax:

Operands:

Operation:

Status Affected:

[ label ] RETLW k

0 ≤ k ≤ 255

k → (W);

TOS → PC

None

Encoding:

11

01xx kkkk kkkk

Description:

The W register is loaded with the eight-

bit literal ’k’. The program counter is

loaded from the top of the stack (the

return address). This is a two-cycle

instruction.

Words:

1

Cycles:

2

Q Cycle Activity:

Q1

Q2

Q3

Q4

1st Cycle

Decode

Read

literal ’k’

No

Operation

Write to W,

Pop from

the Stack

2nd Cycle No

No

No

No

Operation Operation Operation Operation

Example

CALL TABLE ;W contains table

;offset value

;W now has table value

•

•

TABLE ADDWF PC

RETLW k1

RETLW k2

•

•

•

RETLW kn

Before Instruction:

W = 0x07

;W = offset

;Begin table

;

; End of table

After Instruction:

W = value of k8

DS39544A-page 126

Preliminary

 2001 Microchip Technology Inc.

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