INDORE INSTITUTE OF SCIENCE & TECHNOLOGYDEPARTMENT OF ELECTRONICS & COMMUNICATION ENGINEERING

Experiment Number-: 10

AIM: - To Study and Verify BCD to Excess-3 Code Converter.

OBJECTIVE: To understand the logic of different following logic circuit

1. BCD to Excess- 3 Code 2. Excess-3 to BCD Code.

APPARATUS REQUIRED:-IC 7483, IC 7486, Patch Cords & IC Trainer Kit.

THEORY:-

Code converter is a combinational circuit that translates the input code word into a new corresponding word. The excess-3 code digit is obtained by adding three to the corresponding BCD digit. To Construct a BCD-to-excess-3-code converter with a 4-bit adder feed BCD code to the 4-bit adder as the first operand and then feed constant 3 as the second operand. The output is the corresponding excess-3 code. To make it work as a excess-3 to BCD converter, we feed excess-3 code as the first operand and then feed 2's complement of 3 as the second operand. The output is the BCD code

BCD TO EXCESS-3 CONVERTOR TRUTH TABLE:

B3 B2 B1 B0 G3 G2 G1 G0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1

0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1

0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1

0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1

0 0 0 0 0 1 1 1 1 1 x x x x x x

0 1 1 1 1 0 0 0 0 1 x x x x x x

1 0 0 1 1 0 0 1 1 0 x x x x x x

1 0 1 0 1 0 1 0 1 0 x x x x x x

DIGITAL CIRCUIT AND SYSTEM LAB MANUAL

LOGIC DIAGRAM OF BCD TO EXCESS-3 CONVERTOR :

EXCESS-3 TO BCD CONVERTOR TRUTH TABLE

B3 B2 B1 B0 G3 G2 G1 G0

0000011111

0111100001

1001100110

1010101010

0000000011

0000111100

0011001100

0101010101

DIGITAL CIRCUIT AND SYSTEM LAB MANUAL

LOGIC DIAGRAM OF EXCESS-3 TO BCD CONVERTOR:

PROCEDURE:- Connections were given as per circuit diagram. Logical inputs were given as per truth table Observe the logical output and verify with the truth tables.

RESULT:- Thus BCD to excess-3 code converter and Excess-3 to BCD code converter was designed and implemented.

DIGITAL CIRCUIT AND SYSTEM LAB MANUAL