DP83266 datasheet(22/152 Pages) NSC

Il numero della parte	DP83266

Spiegazioni elettronici	MACSITM Device (FDDI Media Access Controller and System Interface)

PDF	152 Pages

Scroll/Zoom	100%

Produttore elettronici	NSC [National Semiconductor (TI)]

Homepage	http://www.national.com

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50 Functional Description (Ring Engine) (Continued)

If any frame of a service opportunity requests this option

then all frames on that service opportunity will be stripped

using this method Void Stripping is invoked upon the asser-

tion of the STRIP signal at the beginning of a frame trans-

mission

Void Stripping is also automatically invoked by this station if

it wins the Claim token process before the initial token is

issued This removes all fragments and ownerless frames

from the ring when the ring becomes operational

FCS Transparency

Normally the Ring Engine generates and transmits the

FCS When the Frame Check Sequence Transparency op-

tion is selected the Ring Engine device does not append

the FCS to the end of the Information field This option is

selected by asserting signal FCST

The receiving stations treat the last four bytes of the data

stream as the FCS

This option may be useful for end to end FCS coverage

when crossing FDDI bridges for diagnostic purposes or in

Implementer frames

54 FRAME VALIDITY PROCESSING

A valid frame is a frame that meets the minimum length

criteria and contains an integral number of data symbol

pairs between the Starting and Ending Delimiters as shown

in Table 5-4

DP83266 Scheda tecnica(PDF) 22 Page - National Semiconductor (TI)