PIC16F639 Microchip Technology Inc., PIC16F639 Datasheet - Page 157

• Manufacturer Part Number: PIC16F639
• Description: 8/14-pin Flash-based, 8-bit Cmos Microcontrollers With Nanowatt Technology
• Manufacturer: Microchip Technology Inc.

RETFIE
Syntax:
Operands:
Operation:
Status Affected:
Description:
Words:
Cycles:
Example:
© 2007 Microchip Technology Inc.
Return from Interrupt
[ label ]
None
TOS
1
None
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
After Interrupt
RETFIE
GIE
PC,
PC =
GIE =
RETFIE
TOS
1
PIC12F635/PIC16F636/639
RETLW
Syntax:
Operands:
Operation:
Status Affected:
Description:
Words:
Cycles:
Example:
TABLE
RETURN
Syntax:
Operands:
Operation:
Status Affected:
Description:
Return from Subroutine
[ label ]
None
TOS
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.
Return with literal in W
[ label ]
0
k
TOS
None
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
Before Instruction
After Instruction
CALL TABLE;W contains
table
•
•
•
ADDWF PC ;W = offset
RETLW k1 ;Begin table
RETLW k2 ;
•
•
•
RETLW kn ; End of table
k
(W);
;offset value
;W now has table value
255
PC
PC
W
W
RETURN
RETLW k
=
=
DS41232D-page 155
0x07
value of k8