Patent · US Expired

Method and structure for implementing a cache memory using a DRAM array

US5829026A · kind A · utility

334Cited by
10References
47Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 5, 1997
Grant dateOct 27, 1998
Priority date
Expiry dateMar 5, 2017

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06F12/0893
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

A method and structure for implementing a DRAM memory array as a second level cache memory in a computer system. The computer system includes a central processing unit (CPU), a first level SRAM cache memory, a CPU bus coupled to the CPU, and a second level cache memory which includes a DRAM array coupled to the CPU bus. When accessing the DRAM array, row access and column decoding operations are performed in a self-timed asynchronous manner. Predetermined sequences of column select operations are then performed in a synchronous manner with respect to a clock signal. The DRAM array is operated at a higher frequency than the frequency of the CPU bus clock signal, thereby reducing the access latency of the DRAM array. By operating the DRAM array at a higher frequency than the CPU bus, additional time is provided for precharging the DRAM array. As a result, the precharging of the DRAM array is transparent to the CPU bus.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.