Browse Prior Art Database

Translation Look-Aside Buffer-Unified Cache Memory

IP.com Disclosure Number: IPCOM000113118D
Original Publication Date: 1994-Jul-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 65K

Publishing Venue

IBM

Related People

Oba, N: AUTHOR [+2]

Abstract

This article describes a new implementation scheme for a Translation Look-Aside Buffer (TLB) and a cache memory. This scheme unifies the cache tag memory with the TLB so that:

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 53% of the total text.

Translation Look-Aside Buffer-Unified Cache Memory

      This article describes a new implementation scheme for a
Translation Look-Aside Buffer (TLB)  and a cache memory.  This
scheme unifies the cache tag memory with the TLB so that:

1.  It reduces the  total amount of high-speed memories  for the
    cache tag and TLB memories.

2.  It unifies  the detection  of a  TLB hit  and a  cache hit.
    This consequently simplifies the logic and makes it operate
    faster.

3.  It can easily be extended to  the scheme that consistently
    manages a second-level  cache memory as well  as a first-level
    one.   This significantly reduces the  hardware amount, shortens
    the  time for detecting  a cache  hit,  and  simplifies the
    inclusion  property control.

      Fig. 1 depicts  the configuration  of the  scheme.   The cache
tag memory  is completely  unified  to the  TLB,  which  contains a
cache control field in addition to the standard TLB fields.

      In the configuration  where the page size  is N times as  large
as the cache line size, the cache control field in each TLB entry
consists of N cache status subfields.  Each cache status subfield is
composed of a valid flag and a location tag.   The valid flag
indicates if the cache data memory stores a  valid data.  The
location tag  specifies the set number if the cache  is of set
associative type.   The location tag is not needed if the cache is of
direct-mapping type.

Define the parameters...