Fast data retrieval from real addressable data storage using memory page crossing prediction comment

摘要

In a computer system having a virtual addressing address space divided into a number of pages, the real addressing data structure and its complementary selection data structure provide complementary memory page crossing prediction storage, latches, and comparators. The memory page crossing prediction memory structure is used to store a plurality of memory page crossing prediction comments corresponding to the contents of the data and the selection data storage structure. Each memory page crossing prediction comment predicts whether the current access will cross a new memory page. The latch is used to sequentially record the first portion of each real address of the accessed real address to which the accessed virtual address has been translated from each counterpart. The first portion of the recorded real address of the immediately preceding access is used to select the data currently read from the memory structure if the currently read memory page crossing prediction comment predicts the memory page crossing nothing. The comparator is used to determine if the first real address portion of the previous access matches the first real address portion of the current access, if it is used to select data for the current access. Corrective actions, including verifying selected data and correcting incorrect memory page crossing prediction comments, are performed when the two real addresses are determined to be inconsistent. As a result, most data retrieval is implemented without having to wait for the first part of the accessed real address to be translated, thereby improving the performance of retrieving data from the real addressable data structure.