Question

National University of Computer and Emerging Sciences School of Engineering Islamabad Campus b. Consider Fig 2.2, now the combinational cicuit has four BCD inputs (lo to l). Design the combinational circuit (at block level) so that when select '00, the four bit BCD number appearing at lo is displayed at segment 1, when select '01', the four bit BCD number appearing at Is is displayed at segment 2 and so on. [10] 4 bit lo 4 bit 7 bit 4 bit 4 bit COMBINATIONAL la CIRCUIT 2 bit select Fig 2.2

Answer 1

Combinstionsl circuit oBCD to 7 abcdefg segment 121 BCD to7 sment l2a lai BCD to 7 abcdefg Selecto

1. here we have to use 4 BCD to 7 segment decoder to display digits from 0 to 9,each BCD to 7 segment decoder has 4 bit inputs and 7 outputs(a,b,c,d,e,f,g).

2. need to use 2 to 4 decoder to select one of four 7 segment display.when select0=0 & select1=0 it selects e3 7 segment display.when select0=0 & select1=1 it selects e2 7 segment display.when select0=1 & select1=0 it selects e1 7 segment display.when select0=1 & select1=1 it selects e0 7 segment display,