| 摘要 |
PURPOSE: To make many registers flexibly accessible by selecting a register to be used for data processing from each of a plurality of sets of registers for holding data to be processed and not using the other registers than the selected register. CONSTITUTION: A system incorporates, for example, twelve sets of registers 2. When a resistor selection instruction is executed in a central processing unit, twelve control fields for the sets of registers 2 are loaded in a control field store 18. The values of the control fields are first impressed upon exclusive OR gates 12 and 14 and the output signals of the gates 12 and 14 obtained as a result of the impressed values are held in latches 8 and 10 and control a four-way multiplexer 4. In such a way, for example, selected register sets 20, 22, 24, and 26 are connected to a register bus 28. Therefore, many registers can be accessed flexibly. |
