PIC16C620 Microchip Technology, PIC16C620 Datasheet - Page 69

• Manufacturer Part Number: PIC16C620
• Description: EPROM-Based 8-Bit CMOS Microcontroller
• Manufacturer: Microchip Technology

NOP
Syntax:
Operands:
Operation:
Status Affected:
Encoding:
Description:
Words:
Cycles:
Example
OPTION
Operands:
Syntax:
Operation:
Status Affected: None
Encoding:
Description:
Words:
Cycles:
Example
1998 Microchip Technology Inc.
No Operation
[ label ]
None
No operation
None
No operation.
1
1
Load Option Register
[ label ]
None
(W)
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.
1
1
To maintain upward compatibility
with future PICmicro™ products,
do not use this instruction.
NOP
00
00
OPTION
NOP
OPTION
0000
0000
0110
0xx0
0010
0000
Preliminary
RETFIE
Syntax:
Operands:
Operation:
Status Affected:
Encoding:
Description:
Words:
Cycles:
Example
RETLW
Syntax:
Operands:
Operation:
Status Affected:
Encoding:
Description:
Words:
Cycles:
Example
TABLE
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
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
CALL TABLE
•
value
•
•
ADDWF PC
RETLW k1
RETLW k2
•
•
•
RETLW kn
Before Instruction
After Instruction
RETFIE
00
11
k
(W);
GIE
PIC16C62X
255
PC,
PC
PC =
GIE =
W
W
RETFIE
RETLW k
0000
01xx
=
=
;W contains table
;offset value
;W now has table
;W = offset
;Begin table
;
; End of table
DS30235G-page 69
TOS
1
0x07
value of k8
0000
kkkk
1001
kkkk