| 摘要 |
PURPOSE:To reduce lowering of performance in the case of cash mistake by providing a function of transferring reading request of data and memory address in a cash memory and a main memory simultaneously in a data processing device. CONSTITUTION:When an arithmetic processing unit 1 requests taking out of instruction and operand, request for reading out data is given to a cash memory 2 and a main memory 3 simultaneously, and data address is transferred by an address line 12. The main memory 3 starts reading of data regardless of whether this request makes cash hit or not. On the other hand, the cash memory section 2 investigates whether requested data exist in the section or not. In the case of cash hit, data are read out from the cash memory section 2 and transferred to the arithmetic unit 1 through a data line 13. At the same time, instruction to stop reading operation is given to the main memory 3, and the main memory 3 stops reading operation of data thereafter. |
