PIC16F946 Datasheet, PDF (222/274 Pages) Microchip Technology – 64-Pin Flash-Based, 8-Bit CMOS Microcontrollers with LCD Driver and nanoWatt Technology

PIC16F946
RETFIE
Syntax:
Operands:
Operation:
Status Affected:
Encoding:
Description:
Words:
Cycles:
Example:
Return from Interrupt
[ label ] RETFIE
None
TOS → PC,
1 → GIE
None
00 0000 0000 1001
Return from Interrupt. Stack is
POPed and Top-of-Stack (TOS) is
loaded in the PC. Interrupts are
enabled by setting Global Interrupt
Enable bit, GIE (INTCON<7>).
This is a two-cycle instruction.
1
2
RETFIE
After Interrupt
PC =
GIE =
TOS
1
RETLW
Syntax:
Operands:
Operation:
Status Affected:
Encoding:
Description:
Words:
Cycles:
Example:
TABLE
Return with Literal in W
[ label ] RETLW k
0 ≤ k ≤ 255
k → (W);
TOS → PC
None
11 01xx kkkk kkkk
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.
1
2
CALL TABLE ;W contains table
;offset value
•
;W now has table
value
•
•
ADDWF PC ;W = offset
RETLW k1 ;Begin table
RETLW k2 ;
•
•
•
RETLW kn ; End of table
Before Instruction
W = 0x07
After Instruction
W = value of k8
RETURN
Syntax:
Operands:
Operation:
Status Affected:
Description:
Return from Subroutine
[ label ] RETURN
None
TOS → PC
None
Return from subroutine. The stack
is POPed and the top of the stack
(TOS) is loaded into the program
counter. This is a two-cycle
instruction.
DS41265A-page 220
Preliminary
© 2005 Microchip Technology Inc.