
1997 Microchip Technology Inc.
DS30272A-page 79
PIC16C71X
NOP
No Operation
Syntax:
[
label ]
NOP
Operands:
None
Operation:
No operation
Status Affected:
None
Encoding:
00
0000
0xx0
0000
Description:
No operation.
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
NOP
Example
NOP
OPTION
Load Option Register
Syntax:
[
label ]
OPTION
Operands:
None
Operation:
(W)
→ OPTION
Status Affected: None
Encoding:
00
0000
0110
0010
Description:
The contents of the W register are
loaded in the OPTION register. This
instruction is supported for code com-
patibility with PIC16C5X products.
Since OPTION is a readable/writable
register, the user can directly address
it.
Words:
1
Cycles:
1
Example
To maintain upward compatibility
with future PIC16CXX products, do
not use this instruction.
RETFIE
Return from Interrupt
Syntax:
[
label ]
RETFIE
Operands:
None
Operation:
TOS
→ PC,
1
→ GIE
Status Affected:
None
Encoding:
00
0000
1001
Description:
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.
Words:
1
Cycles:
2
Q Cycle Activity:
Q1
Q2
Q3
Q4
1st Cycle
Decode
NOP
Set the
GIE bit
Pop from
the Stack
2nd Cycle
NOP
Example
RETFIE
After Interrupt
PC =
TOS
GIE =
1