PIC17C756A MICROCHIP [Microchip Technology], PIC17C756A Datasheet - Page 221

• Manufacturer Part Number: PIC17C756A
• Description: High-Performance 8-bit CMOS EPROM Microcontrollers with 10-bit A/D
• Manufacturer: MICROCHIP [Microchip Technology]

RETFIE
Syntax:
Operands:
Operation:
Status Affected:
Encoding:
Description:
Words:
Cycles:
Q Cycle Activity:
Example:
2000 Microchip Technology Inc.
After Interrupt
operation
Decode
PC
GLINTD =
Q1
No
=
operation
operation
Return from Interrupt
[ label ]
None
TOS
0
PCLATH is unchanged.
GLINTD
Return from Interrupt. Stack is POP’ed
and Top-of-Stack (TOS) is loaded in the
PC. Interrupts are enabled by clearing
the GLINTD bit. GLINTD is the global
interrupt disable bit (CPUSTA<4>).
1
2
RETFIE
0000
Q2
No
No
TOS
0
GLINTD;
(PC);
RETFIE
0000
operation
GLINTD
Clear
Q3
No
0000
from stack
operation
POP PC
Q4
No
0101
RETLW
Syntax:
Operands:
Operation:
Status Affected:
Encoding:
Description:
Words:
Cycles:
Q Cycle Activity:
Example:
Before Instruction
After Instruction
operation
Decode
WREG
WREG
Q1
No
=
=
operation
Return Literal to WREG
[ label ]
0
k
PCLATH is unchanged
None
WREG is loaded with the eight-bit literal
'k'. The program counter is loaded from
the top of the stack (the return address).
The high address latch (PCLATH)
remains unchanged.
1
2
TABLE
literal 'k'
Read
1011
Q2
No
CALL TABLE ; WREG contains table
:
ADDWF PC
RETLW k0
RETLW k1
:
:
RETLW kn
0x07
value of k7
k
(WREG); TOS
PIC17C7XX
255
RETLW k
0110
operation
Process
;
;
;
; WREG = offset
; Begin table
;
; End of table
Data
Q3
No
DS30289B-page 221
offset value
WREG now has
table value
kkkk
(PC);
from stack,
operation
POP PC
Write to
WREG
Q4
No
kkkk