MULTIPLE VIRTUAL ADDRESSING USING/COMPARING TRANSLATION PAIRS OF ADDRESSES COMPRISING A SPACE ADDRESS AND AN ORIGIN ADDRESS (STO) WHILE USING SPACE REGISTERS AS STORAGE DEVICES FOR A DATA PROCESSING SYSTEM

摘要

Instead of translation from a space address to a segment table origin address (STO) by an ordinary instruction, translation to the STO is done by a space base register modify instruction which uses an instruction to modify the content of the space register, and the result thereof is used for the operand address calculation of the instruction to the operand data fetching. The present system eliminates the need for additionally providing for hardware of an operand fetch unit hardware for the translation from the space address to the STO, memory for storing translation pairs of the space addresses and the STO's and the table look-up of the translation pairs. Thus, degradation of performance is minimized with less hardware.