Direct Address to Critical Arrays
Original Publication Date: 1987-Mar-01
Included in the Prior Art Database: 2005-Feb-01
When an access is made by an instruction processing unit (IPU) to write data into or fetch data from a data cache, three operations are performed. The address must be translated from Virtual to Real, the request must be checked for proper authority, and the cache directory has to be searched. To accomplish these tasks, external arrays are used to store information and the time required to extract this information from the external arrays becomes an important factor in determining the amount of time required to get data back to the IPU. The writing of data into or fetched from the data cache is accomplished in a time saving manner in the following implementation. As seen in Fig. 1, the previous configuration, an address is received from the IPU and starts the entire process.