PIC16F627A_05 Datasheet, PDF (127/180 Pages) Microchip Technology – Flash-Based, 8-Bit CMOS Microcontrollers with nanoWatt Technology

PIC16F627A/628A/648A
RETLW
Syntax:
Operands:
Operation:
Status Affected:
Encoding:
Description:
Words:
Cycles:
Example
TABLE
Return with Literal in W
[ label ] RETLW k
0 ≤ k ≤ 255
k → (W);
TOS → PC
None
11
01xx kkkk kkkk
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;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 = 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
© 2005 Microchip Technology Inc.
DS40044D-page 125