Bitstellen

Bitstellen is a term used in digital electronics and computer science to denote the position of an individual binary digit within a fixed-width word or data unit. In German-language terminology, Bitstelle means bit position or bit place, with Bitstellen referring to multiple positions. In most programming and hardware contexts, bit positions are numbered starting at zero for the least significant bit (LSB). For example, in an 8-bit byte, bit 0 corresponds to the value 1, bit 3 to 8, and bit 7 to 128. Bit masks specify a bit's position by setting the corresponding bit; for instance, the mask 0x08 targets bit 3, and 0x20 targets bit 5. Shifting operations move bits between positions, enabling extraction, testing, setting, or clearing of specific bits.

Bit numbering is typically defined within a byte; when dealing with multi-byte words, endianness determines the byte order, but the bit positions within each byte are usually described independently. In practice, bitstellen appear in device registers, communication protocols, and low-level software, where precise control of individual bits is required. They are essential for bit fields, flags, and control bits in status registers and configuration words.

Variations exist between languages and architectures regarding whether bit numbering starts at zero or one, and whether bit 0 is the least significant or most significant in certain contexts. Therefore, explicit masks and documented conventions are preferred to avoid ambiguity.

See also: bit mask, bit field, endianness, register, bitwise operations.