How to Calculate CRC Made Easy

Binary data uses ones and zeros to represent numbers.

CRC (Cyclic Redundancy Check) calculations involve binary calculations which provide data to test the integrity of a string of data on a computer. Data is stored in strings of ones and zeros on computers because the bit on a computer is either zapped or not zapped. This is called binary notation. CRC calculations are used to determine whether data is corrupted when it is transferred to a disc or across a network.

Instructions

1. Convert the data into binary (see Resources).

2. Select an odd number for a key and convert it to binary (see Resources).

3. Divide the data (in binary) by the key (also in binary). This process involves simple long division. Since only 1 and 0 are used, simply compare the string for each place. If the dividend (number being divided) is greater than the divisor (number to divide by), place a 1. If the dividend is smaller than the divisor, place a 0. Put a hyphen before the remainder, but keep the remainder. The total value including the remainder is the CRC value.

References

• Lammer Tables: On-line CRC calculation and free library
• AAA Math: Division Terms

Resources

• Dewassoc: Decimal, Hexadecimal Binary Conversion Table