IDEC FC4A-C10R2 User Manual page 205

Bidirectional Shift Register
A bidirectional shift register can be created by first programming the SFR instruction as detailed in the Forward Shift Reg-
ister section on page 7-18. Next, the SFRN instruction is programed as detailed in the Reverse Shift Register section on
page 7-20.
Ladder Diagram
Reset
SFR R22
6
I1
Pulse
I2
Data
I3
Reset
SFRN R22
6
I4
Pulse
I5
Data
I6
R23 Q0
R24 Q1
R26 Q2
Structural Diagram
First Bit: R22
Reset
I1
Data
R22 R23 R24 R25
I3
Pulse
Last Bit: R22
I2
Note: Output is initiated only for those bits highlighted in bold print.
Program List
Instruction
LOD
LOD
LOD
SFR
LOD
LOD
LOD
SFRN
LOD
OUT
LOD
OUT
LOD
OUT
Forward Shifting
# of Bits: 6
Reset
Data
R26 R27
Pulse
# of Bits: 6
Reverse Shifting
« FC4A M
Data
I1
I2
I3
R22
6
I4
I5
I6
R22
6
R23
Q0
R24
Q1
R26
Q2
I4
I6
I5
S U ' M
ICRO MART SER S ANUAL
7: B
ASIC
»
I
NSTRUCTIONS
7-21