PIC17C4X
RETURN
Return from Subroutine
RLCF
Rotate Left f through Carry
[ label ] RLCF f,d
0 ≤ f ≤ 255
Syntax:
[ label ] RETURN
None
Syntax:
Operands:
Operands:
Operation:
Status Affected:
Encoding:
Description:
d
[0,1]
TOS → PC;
None
Operation:
f<n> → d<n+1>;
f<7> → C;
C → d<0>
0000
0000
0000
0010
Return from subroutine. The stack is
popped and the top of the stack (TOS)
is loaded into the program counter.
Status Affected:
Encoding:
C
0001
101d
ffff
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
WREG. If 'd' is 1 the result is stored
back in register 'f'.
Description:
Words:
Cycles:
1
2
Q Cycle Activity:
Q1
Q2
Q3
Q4
register f
C
Decode
Read
register
PCL*
Execute
NOP
Words:
Cycles:
1
1
Forced NOP
NOP
Execute
NOP
* Remember reading PCL causes PCLATH to be updated.
This will be the high address of where the RETURNinstruc-
tion is located.
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register 'f'
Execute
Write to
destination
RETURN
Example:
After Interrupt
RLCF
REG,0
Example:
PC = TOS
Before Instruction
REG
=
1110 0110
C
=
0
After Instruction
REG
WREG
C
=
=
=
1110 0110
1100 1100
1
DS30412C-page 132
1996 Microchip Technology Inc.
MICROCHIP [ MICROCHIP ]
