PIC16C55X_13 Datasheet, PDF (62/108 Pages) Microchip Technology – EPROM-Based 8-Bit CMOS Microcontrollers

PIC16C55X
RETFIE
Syntax:
Operands:
Operation:
Status Affected:
Encoding:
Description:
Words:
Cycles:
Example
Return from Interrupt
[ label ] RETFIE
None
TOS  PC,
1  GIE
None
00
0000 0000 1001
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
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 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
CALL TABLE;W contains table
;offset value
•
;W now has table
value
•
•
ADDWF PC ;W = offset
TABLE RETLW k1 ;Begin table
RETLW k2 ;
•
•
•
RETLW kn ; End of table
Before Instruction
W = 0x07
After Instruction
W = value of k8
RETURN
Syntax:
Operands:
Operation:
Status Affected:
Encoding:
Description:
Words:
Cycles:
Example
Return from Subroutine
[ label ] RETURN
None
TOS  PC
None
00
0000 0000 1000
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.
1
2
RETURN
After Interrupt
PC = TOS
RLF
Syntax:
Operands:
Operation:
Status Affected:
Encoding:
Description:
Rotate Left f through Carry
[ label ] RLF f,d
0  f  127
d  [0,1]
See description below
C
00
1101 dfff ffff
The contents of register 'f' are rotated
one bit to the left through the Carry
Flag. If 'd' is 0 the result is placed in
the W register. If 'd' is 1 the result is
stored back in register 'f'.
C
Register f
Words:
Cycles:
Example
1
1
RLF
REG1,0
Before Instruction
REG1 = 1110 0110
C
=0
After Instruction
REG1 = 1110 0110
W
= 1100 1100
C
=1
DS40143E-page 62
Preliminary
 1996-2013 Microchip Technology Inc.