Data processing apparatus

摘要

A data processing apparatus uses a stored-program method to execute an operation instructed by an instruction word that includes a register designation code as an operand. A plurality of work registers are identifiable by register numbers, each of a typical number of bits. A correspondence table holds at least one of the register numbers in a state corresponding to register designation codes. The codes are stored in a readable condition, and have fewer bits than the register numbers. The data processing apparatus refers to the correspondence table when executing the operation.