
1999 Microchip Technology Inc.
DS40182C-page 73
PIC16CE62X
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
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
compatibility 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 PICmicro 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
setting Global Interrupt Enable bit,
GIE (INTCON<7>). This is a two-cycle
instruction.
Words:
1
Cycles:
2
Example
RETFIE
After Interrupt
PC =
TOS
GIE =
1
RETLW
Return with Literal in W
Syntax:
[
label ]
RETLW k
Operands:
0
≤ k ≤ 255
Operation:
k
→ (W);
TOS
→ PC
Status Affected:
None
Encoding:
11
01xx
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
Example
TABLE
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