Binary-coded decimal Binary-coded decimal In computing and electronic systems, binary-coded decimal (BCD) is a class of binary encodings of decimal numbers where each decimal digit is represented by a fixed number of bits, usually four or eight. Special bit patterns are sometimes used for a sign or for other indications (e.g., error or overflow). In byte-oriented systems (i.e. most modern computers), the term "unpacked" BCD usually implies a full byte for each digit (often including a sign), whereas "packed" BCD typically encodes two decimal digits within a single byte by taking advantage of the fact that four bits are enough to represent
Byte-oriented protocol bytes per code point. Byte-oriented protocol Byte-oriented framing protocol is "a communications protocol in which full bytes are used as control codes. Also known as character-oriented protocol." For example UART communication is byte-oriented. The term "character-oriented" is deprecated, since the notion of character has changed. An ASCII character fits to one byte (octet) in terms of the amount of information. With the internationalization of computer software, wide characters became necessary, to handle texts in different languages. In particular, Unicode characters (or strictly speaking code points) can be 1, 2, 3 or 4 bytes in UTF-8, and other encodings of Unicode