Datasheet

© 2006 Microchip Technology Inc. DS41159E-page 313
PIC18FXX8
RETURN Return from Subroutine
Syntax: [
label ] RETURN [s]
Operands: s ∈ [0,1]
Operation: (TOS) → PC,
if s = 1
(WS) → W,
(STATUSS) → Status,
(BSRS) → BSR,
PCLATU, PCLATH are unchanged
Status Affected: None
Encoding: 0000 0000 0001 001s
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: 1
Cycles: 2
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode No
operation
Process
Data
Pop PC
from stack
No
operation
No
operation
No
operation
No
operation
Example:
RETURN
After Interrupt
PC = TOS
RLCF Rotate Left f through Carry
Syntax: [
label ] RLCF f [,d [,a]]
Operands: 0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operation: (f<n>) → dest<n + 1>,
(f<7>) → C,
(C) → dest<0>
Status Affected: C, N, Z
Encoding: 0011 01da ffff ffff
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
will be selected, overriding the BSR
value. If ‘a’ = 1, then the bank will be
selected as per the BSR value (default).
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
Example:
RLCF REG, W
Before Instruction
REG = 1110 0110
C=0
After Instruction
REG = 1110 0110
W = 1100 1100
C=1
C
register f