83C795 Datasheet, PDF (92/136 Pages) List of Unclassifed Manufacturers – Ethernet System Controller

LAN CONTROLLER OVERVIEW
7.6.7.6 Extensions Beyond 802.3 10Base5
Protocol
T he 802.3 10Bas e5 protocol utilizes frame lengths
between 64 and 1518 bytes inclus ively. T he
trans mitter s ection is capable of sending frames
greater than 17 and les s than 32,768 bytes in
length. T ransmis sion of longer or shorter frames
than permitted within the 10Base5 definition may
be us eful in other variations of 802.3 protocols .
When consideringthe trans mis s ion of giant frames
on a non-802.3 network, be aware that very long
frames can activate jabber detectors in exis ting
10Bas eX MAUs and repeaters . T he use of s uch
fr ames in non-s tandard networks requires
cons iderable planning and s ome caution.
To s upport non-802.3 protocols, the 83C795’s s lot
time is program-selectable. Choose from 256-bit,
512-bit, or 1024-bit times.
T heS topBackoff algorithmis s electablefor backoff
modification following collis ions .
When operatingin ALT E GOMode, detection of any
pair of consecutive ’0’ bits within the preamble
caus es the reception of that fr ame to be
abandoned. No error is reported.
T he R CON.R CA bit enables the receiver to
abandon reception of any frame which caus es a
collis ion. No error is reported.
7.6.7.7 Extended Length
When the XL E NGT H bit (GCR .7) is s et, the
twisted-pair port can be connectedtocables longer
than the 100-meter limit specified by the 802.3
s pecification
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