ENS221/CSC 347 Prof. Herb Schanker

Lab 5

Name ________________________

See Text --- Adders & Subtractors pp 452 to 455

All circuits that are to be realized must use first multisims and compare resulting truth table outputs with hardware.

Realize the circuits for

a) Half-Adder (use only 7400 and 7486 chips). Inputs are to use 7493 binary counter.

b) Full-Adder (use only 7400 and 7486 chips). Inputs are to use 7493 binary counter.

c) Parallel Adder (use 7483 and 7493 for ‘B’ binary inputs)

1. ‘A’ inputs should be hardwired to the power supply and ground to produce 1001.

2. ‘B’ inputs should use 7493 to produce 3 binary digits of 0101, 1001, and 1111.

3. The carry in input, C0, should be hardwired to be both 0 and 1 for the first case of adding B input of 0101(5) and 0 for the other two input cases given above.

d) Adder – Subtractor (use 7483, 7486 and 7493 for ‘B’ binary inputs)

Do for examples of

1. 9 + 5 and 9 – 5

2. 9 + 9 and 9 – 9

3. 9 + 15 and 9 – 15

** e) Magnitude Comparator

** The author states that you can realize this circuit with two

additional chips, a 7404 INVERTER and a 7408 AND chip. There are

actually four 2 - chip realizations:

INVERTER with an -- AND or OR or NAND or NOR.

On paper determine the circuit for these four realizations ( 2 input gates) and

implement in multisims and hardware the inverter - nor (7402) circuit. Test with

1. 9 – 9
2. 9 – 8
3. 9 – 10

NB -- Fixed binary number input means you tie the input pins to the

respective bus, power or ground, in order to form the number.