Processor cycle tracking in a controller for two-way set associative cache
US5392417A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 1, 1994 |
| Grant date | Feb 21, 1995 |
| Priority date | — |
| Expiry date | Mar 1, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F12/0879
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A processor communicates over a memory bus with a main memory and a cache by asserting an address strobe signal (ADS) to initiate a memory access. The cache includes a cache controller and a tag random access memory (tag RAM). Internal cycles are tracked by a first logic in the tag RAM that responds to an external cycle (EXCYC) signal and asserts an internal cycle (INCYC) signal during a time when a request to the tag RAM is pending. A second logic combines the INCYC signal with the. ADS to generate an address strobe wait (ADSWAIT) signal. A third logic combines the ADSWAIT signal with the ADS to generate an address strobe cycle (ADSCYC) signal. A fourth logic responsive to one of several end-of-cycle signals generates a terminate signal to signify an end of a current cycle. A fifth logic asserts the EXCYC signal in response to the ADSCYC signal and unasserts the EXCYC signal in response to the terminate signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.