AM79C90PC datasheet(61/62 Pages) AMD

Part #	AM79C90PC

Description	CMOS Local Area Network Controller for Ethernet (C-LANCE)

PDF	62 Pages

Scroll/Zoom	100%

Manufacturer	AMD [Advanced Micro Devices]

Direct Link	http://www.amd.com

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61 / 62 page

Am79C90

17. Elimination of Burn-In Option

The burn-in option for the C-LANCE is no longer avail-

able. Thus, the ordering part number Am79C90PCB is

no longer valid (see page 4 of the C-LANCE data

sheet).

18. RX Descriptor Zero Buffer Byte Count Handling

The 12-bit BCNT ﬁeld in the receive descriptor of the

LANCE and C-LANCE devices is loaded with the 2’s

complement of the number of bytes allocated to the

associated receive buffer. In the LANCE device, when

all 0’s are written to the BCNT ﬁeld in a receive descrip-

tor, a buffer length of 4096 (212) bytes is assumed. In

the C-LANCE device, the case of all 0’s in the receive

descriptor may produce unpredictable results.

This difference should not cause problems in IEEE

802.3-compliant networks, because 802.3 has a maxi-

mum packet length speciﬁcation of 1518 bytes.

AM79C90PC Datasheet(PDF) 61 Page - Advanced Micro Devices