Tech Trill

BCD code

The BCD code is represented using binary digits consisting of four bits.
8421 code is a type of BCD and is composed of four bits representing the
decimal digits 0-9.8421 indicates the binary weight of 4bits.(i.e) two to the
power 3, two to the power 2, two to the power 1 and two to the power 0.
the BCD code for the decimal digits 0-15 are

given below:




Using 4 bits 16 binary numbers 0000 to 1111 can be represented but in BCD
code only 10 of these are used.The remaining 6 code combinations are not used
in bcd code.


Gray code

Gray code is an unweighted code which means that there is no specific
weighted assigned to the bit position.Gray code exhibt only one single bit
change from one code to next code.This propperty is used in the encoders.