Mask register for computer processor.

摘要

In a computer capable of running computer programs of different word sizes on a processor having registers designed to run procedures of a largest one of the word sizes, a register for storing indications of bit positions in addresses which are invalid in a procedure of a particular word size, and apparatus for utilizing the indications of bit positions which are invalid in a procedure of a particular word size to mask the bits of an address in a register so that only valid bits are utilized. <IMAGE>