n bit parallel serial in serial out register

half subtracter

7 segment display

3 bit square generator

nor using nand

parallel register

sr latch

excess 3 to BCD code

excess 3

4 bit ripple

jk flip flop

excess 3 to BCD code

mod3

4 bit binary adder cum subtracter

register

2X2 binary multiplier

half adder

jk flip flop

2*2 binary multiplier

rs latch