alignment Definition alignment Alignment refers to the fact that some microprocessors require the address of a data entity to be aligned to a numeric boundary in memory so that address modulo number equals zero. For ex- ample, the M68000 and the PDP-11 require that an integer be aligned along an even address, i.e., address%2==0. Generally speaking, alignment is a problem only if you write programs in assembly language. For C programs, COHERENT ensures that data types are aligned properly under foreseeable con- ditions. You should, however, beware of copying structures and of casting a pointer to char to a pointer to a struct, for these could trigger alignment problems. Processors react differently to an alignment problem. On the VAX or the i8086, it causes a program to run more slowly, whereas on the M68000 it causes a bus error. ***** See Also ***** data types, definitions COHERENT Lexicon Page 1