PIC16F/LF1946/47
RETURN
Return from Subroutine
RETFIE
Syntax:
Return from Interrupt
[ label ] RETFIE k
None
Syntax:
[ label ] RETURN
None
Operands:
Operation:
Status Affected:
Description:
Operands:
Operation:
TOS PC
None
TOS PC,
1 GIE
Status Affected:
Description:
None
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.
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:
Example:
2
RETFIE
After Interrupt
PC
=
TOS
GIE =
1
RETLW
Syntax:
Return with literal in W
RLF
Rotate Left f through Carry
[ label ] RETLW
0 k 255
k
Syntax:
Operands:
[ label ]
RLF f,d
Operands:
Operation:
0 f 127
d [0,1]
k (W);
TOS PC
Operation:
See description below
C
Status Affected:
Description:
None
Status Affected:
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.
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’.
Words:
1
2
C
Register f
Cycles:
Example:
CALL TABLE;W contains table
;offset value
Words:
1
1
Cycles:
Example:
•
•
•
;W now has table value
TABLE
RLF
REG1,0
Before Instruction
ADDWF PC ;W = offset
RETLW k1 ;Begin table
REG1
C
=
=
1110 0110
0
RETLW k2
;
After Instruction
•
•
•
REG1
W
C
=
=
=
1110 0110
1100 1100
1
RETLW kn ; End of table
Before Instruction
W
=
0x07
After Instruction
W
=
value of k8
DS41414A-page 378
Preliminary
2010 Microchip Technology Inc.
MICROCHIP [ MICROCHIP ]
