orthogonal instruction set

architecture An instruction set where all (or most)

instructions have the same format and all registers and

addressing modes can be used interchangeably - the choices

of op code, register, and addressing mode are mutually

independent (loosely speaking, the choices are

"orthogonal"). This contrasts with some early Intel

microprocessors where only certain registers could be used

by certain instructions.

Examples include the PDP-11, 680x0, ARM, VAX.

(2002-06-26)