1.CKT TO SAY IT IS INVALID BCD NOWHICH GIVEN AS I/P?

2.Construct a BCD-to-excess-3-code converter with a 4-bit adder. Remember that the excess-3code digit is obtained by adding three to the corresponding BCD digit. What must be done tochange the circuit to an excess-3-to-BCD-code converter?

3.Construct a 4-digit BCD adder-subtractor using four BCD adders?

4. It is necessary to design a decimal adder for two digits represented in the excess-3 code. Showthat the correction after adding the two digits with a 4-bit binary adder is as follows:(a) The output carry is equal to the carry from the binary adder.(b) If the output carry = 1, then add 0011.(c) If the output carry = 0, then add 1101.Construct the decimal adder with two 4-bit adders and an inverter.

5. Draw the logic diagram of a 2-to-4-line decoder with only NOR gates. Include an enable input.

6. Construct a 5 x 32 decoder with four 3 x 8 decoders with enable and one 2 x 4 decoder.

7. Construct a 16 x 1 multiplexer with two 8 x 1 and one 2 x 1 multiplexers. Use block diagramsfor the three multiplexers.

8. Implement the Boolean function F(A, B, C, D), which can be expressed as sum of minterms 0,3, 5, 6, 8, 9, 14, and 15, with an 8 x 1 multiplexer.

9. Implement a full-adder with two 4 x 1 multiplexers.

10.Implement the Boolean function F(A, B, C, D), which can be expressed as sum ofminterms 0, 1, 3, 4, 8, 9, and 15, with an 8 x 1 multiplexer, but with inputs A, B, andC connected to selection inputs s2, s1, and s0, respectively.

11. 7 SEG DISPLAY