PIC18F2420/2520/4420/4520
RETURN
Return from Subroutine
RLCF
Rotate Left f through Carry
Syntax:
RETURN {s}
Syntax:
RLCF f {,d {,a}}
Operands:
Operation:
s ∈ [0,1]
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
(TOS) → PC;
if s = 1,
(WS) → W,
Operation:
(f<n>) → dest<n + 1>,
(f<7>) → C,
(C) → dest<0>
(STATUSS) → STATUS,
(BSRS) → BSR,
PCLATU, PCLATH are unchanged
Status Affected:
Encoding:
C, N, Z
Status Affected:
Encoding:
None
0011
01da
ffff
ffff
0000
0000
0001
001s
Description:
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
W. If ‘d’ is ‘1’, the result is stored back
in register ‘f’ (default).
If ‘a’ is ‘0’, the Access Bank is
selected. If ‘a’ is ‘1’, the BSR is used to
select the GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction
operates in Indexed Literal Offset
Addressing mode whenever
Description:
Return from subroutine. The stack is
popped and the top of the stack (TOS)
is loaded into the program counter. If
‘s’= 1, the contents of the shadow
registers, WS, STATUSS and BSRS,
are loaded into their corresponding
registers, W, STATUS and BSR. If
‘s’ = 0, no update of these registers
occurs (default).
Words:
Cycles:
1
2
f ≤ 95 (5Fh). See Section 24.2.3
“Byte-Oriented and Bit-Oriented
Instructions in Indexed Literal Offset
Mode” for details.
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
No
operation
Process
Data
POP PC
from stack
register f
C
No
No
No
No
Words:
Cycles:
1
1
operation
operation
operation
operation
Q Cycle Activity:
Q1
Example:
RETURN
Q2
Q3
Q4
After Instruction:
PC = TOS
Decode
Read
register ‘f’
Process
Data
Write to
destination
Example:
RLCF
REG, 0, 0
Before Instruction
REG
C
=
=
1110 0110
0
After Instruction
REG
=
1110 0110
W
C
=
=
1100 1100
1
© 2008 Microchip Technology Inc.
DS39631E-page 299
MICROCHIP [ MICROCHIP ]
