Q.Why do we use digital codes?

A digital code is a systematic way of representing numbers, letters or other information using groups of binary bits. Codes are used because digital systems can only handle 0s and 1s, and a well-chosen code makes storage, transmission, arithmetic and error detection easier and more reliable.

Codes are first classified by whether the bit positions carry a fixed value. In a weighted code, each bit position has a definite positional weight and the decimal value is the weighted sum of the bits. The 8-4-2-1 BCD code and the 2-4-2-1 code are weighted. In a non-weighted code, the bit positions have no fixed weights, so the value cannot be found by a simple weighted sum. The Excess-3 code and the Gray code are non-weighted. …