Binary Coded Decimal Numbering System otherwise known as BCD Code is a process for converting decimal numbers into their binary equivalents. BCD code is more also known as 8421 BCD code.
The BCD equivalent of a decimal number is written by replacing each decimal digit in the integer and fractional parts with its four bit binary equivalent.
0 0000
1 0001
2 0010
3 0011
4 0100
5 0101
6 0110
7 0111
8 1000
9 1001