TMPR4955AF datasheet(67/168 Pages) TOSHIBA

No. de pieza	TMPR4955AF

Descripción Electrónicos	64-Bit TX System RISC TX49 Family

PDF	168 Pages

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Fabricante Electrónico	TOSHIBA [Toshiba Semiconductor]

Página de inicio	http://www.semicon.toshiba.co.jp/eng

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Chapter 5 Cache Organization

5-7

5.4

The primary cache accessing

Figure 5.4.1 shows the virtual address (VA) index to the primary cache. Each instruction and

data cache size is 32 KB. The virtual address bits be used to index into the primary cache

decided by the cache size.

Tags

Tag line

Data

Data line

VA (12..5)

Stage

WTag

VA (12..5)

Figure 5.4.1 Primary Cache Data and Tag Organization

5.5

Cache States

The section describes about the state of a cache line. The cache line in the TX4955A are in

one of states described in Table 5.5.1.

The I-Cache line is in one of the following states:

• invalid

• valid

The D-Cache line is in one of the following states:

• invalid

• valid

Table 5.5.1 Cache States

Cache line State

Description

Invalid

A cache line that does not contain valid information must be marked invalid, and

cannot be used. A cache line in any other state than invalid is assumed to

contain valid information.

Valid

A cache line contains valid information. The cache line may or not be consistent

with memory and is owned by the processor (see Cache Line Ownership in this

chapter).

TMPR4955AF Datasheet(PDF) 67 Page - Toshiba Semiconductor