Patent · US Expired

Method and apparatus for reducing memory read latency in a shared memory system with multiple processors

US5185875A · kind A · utility

16Cited by
13References
6Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJan 27, 1989
Grant dateFeb 9, 1993
Priority date
Expiry dateJan 27, 2009

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06F12/0817
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

Methods and apparatus for reducing memory read latency for selected data requested by one central processing unit (CPU) and retrieved from another CPU through a system control unit (SCU) with special data transfer cycles. The special data transfer cycles include a first dual operation mode which confirms that the transferred data is the most current and then concurrently writes the CPU transferred data into the SCU main memory while transferring it directly to the requesting CPU, and a second dual operation mode which confirms that only a portion of the transferred data is the most current and then concurrently writes the portion of the transferred data that is most current in the SCU memory and reads the written data that is most current in the SCU memory and reads the written data for transfer to the requesting CPU.

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