PIC16F1938_13 Datasheet, PDF (374/488 Pages) Microchip Technology – 28/40/44-Pin Flash-Based, 8-Bit CMOS Microcontrollers with LCD Driver

PIC16(L)F1938/9
RETFIE
Syntax:
Operands:
Operation:
Status Affected:
Description:
Words:
Cycles:
Example:
Return from Interrupt
[ label ] RETFIE
None
TOS  PC,
1  GIE
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 2-cycle
instruction.
1
2
RETFIE
After Interrupt
PC =
GIE =
TOS
1
RETLW
Syntax:
Operands:
Operation:
Status Affected:
Description:
Words:
Cycles:
Example:
TABLE
Return with literal in W
[ label ] RETLW k
0  k  255
k  (W);
TOS  PC
None
The W register is loaded with the 8-bit
literal ‘k’. The program counter is
loaded from the top of the stack (the
return address). This is a 2-cycle
instruction.
1
2
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=
After Instruction
W=
0x07
value of k8
RETURN
Syntax:
Operands:
Operation:
Status Affected:
Description:
Return from Subroutine
[ label ] RETURN
None
TOS  PC
None
Return from subroutine. The stack is
POPed and the top of the stack (TOS)
is loaded into the program counter.
This is a 2-cycle instruction.
RLF
Syntax:
Operands:
Operation:
Status Affected:
Description:
Words:
Cycles:
Example:
Rotate Left f through Carry
[ label ] RLF f,d
0  f  127
d  [0,1]
See description below
C
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
1
1
RLF
REG1,0
Before Instruction
REG1 =
C
=
After Instruction
REG1 =
W
=
C
=
1110 0110
0
1110 0110
1100 1100
1
DS40001574C-page 374
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