PIC17C44 Datasheet, PDF (132/241 Pages) Microchip Technology – High-Performance 8-Bit CMOS EPROM/ROM Microcontroller

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