1-59Q106.3E6.5_{16}BINARY-CODED DECIMALIn today’s technology, you hear a great deal about microprocessors. A microprocessor is anintegrated circuit designed for two purposes: data processing and control.Computers and microprocessors both operate on a series of electrical pulses called words. A wordcan be represented by a binary number such as 10110011_{2}. The word length is described by the number ofdigits or BITS in the series. A series of four digits would be called a 4-bit word and so forth. The mostcommon are 4-, 8-, and 16-bit words. Quite often, these words must use binary-coded decimal inputs.Binary-coded decimal, or BCD, is a method of using binary digits to represent the decimal digits 0through 9. A decimal digit is represented by four binary digits, as shown below:You should note in the table above that the BCD coding is the binary equivalent of the decimal digit.Since many devices use BCD, knowing how to handle this system is important. You must realizethat BCD and binary are not the same. For example, 49_{10} in binary is 110001_{2}, but 49_{10} in BCD is01001001_{BCD}. Each decimal digit is converted to its binary equivalent.BCD ConversionYou can see by the above table, conversion of decimal to BCD or BCD to decimal is similar to theconversion of hexadecimal to binary and vice versa.For example, let’s go through the conversion of 264_{10} to BCD. We’ll use the block format that youused in earlier conversions. First, write out the decimal number to be converted; then, below each digitwrite the BCD equivalent of that digit:

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