# What is a 4-bit BCD adder?

## What is a 4-bit BCD adder?

A 4-bit binary adder that is capable of adding two 4-bit words having a BCD (binary-coded decimal) format. The result of the addition is a BCD-format 4-bit output word, representing the decimal sum of the addend and augend, and a carry that is generated if this sum exceeds a decimal value of 9.

### How many 4-bit binary adders are there in a BCD adder?

two 4-bit
The 4-bit BCD adder comprises of two 4-bit full adders and a carry detection logic circuit in its conventional architecture. The two 4-bit full adders are basically Ripple carry adders where the carry output of one full adder cell is propagated onto the succeeding full adder cell at each computational stage.

#### What is BCD adder explain with block diagram?

BCD adder refers to a 4-bit binary adder that can add two 4-bit words of BCD format. The output of the addition is a BCD-format 4-bit output word. It can descript the decimal sum of the addend and augend and a carry that is created in case this sum exceeds a decimal value of 9.

What are BCD numbers?

B. D. (Binary Coded Decimal) The storage of numbers in which each decimal digit is converted into a binary number and stored in a single 8-bit byte. For example, a 12-digit decimal number would be represented as 12 bytes. BCD uses more storage for numbers than binary encoding (see below).

What is BCD correction?

In case of BCD the binary number formed by four binary digits, will be the equivalent code for the given decimal digits. In BCD we can use the binary number from 0000-1001 only, which are the decimal equivalent from 0-9 respectively.

## Why do we add 6 in BCD?

When you do math in decimal, if a number is larger than 10 you need to take the modulus of 10 and carry to the next row. Similarly, in BCD math, when the result of the addition is larger than 9 you add 6 to skip the 6 remaining “invalid” values and carry to the next digit.

### What is BCD adder example?

When we are simply adding A and B, then we get the binary sum. Here, to get the output in BCD form, we will use BCD Adder. Example 1: Input : A = 0111 B = 1000 Output : Y = 1 0101 Explanation: We are adding A(=7) and B(=8).