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1Notes on the DEC FDDIcontroller 700 (DEFZA-xx) driver v.1.1.4.
2
3
4DEC FDDIcontroller 700 is DEC's first-generation TURBOchannel FDDI
5network card, designed in 1990 specifically for the DECstation 5000
6model 200 workstation.  The board is a single attachment station and
7it was manufactured in two variations, both of which are supported.
8
9First is the SAS MMF DEFZA-AA option, the original design implementing
10the standard MMF-PMD, however with a pair of ST connectors rather than
11the usual MIC connector.  The other one is the SAS ThinWire/STP DEFZA-CA
12option, denoted 700-C, with the network medium selectable by a switch
13between the DEC proprietary ThinWire-PMD using a BNC connector and the
14standard STP-PMD using a DE-9F connector.  This option can interface to
15a DECconcentrator 500 device and, in the case of the STP-PMD, also other
16FDDI equipment and was designed to make it easier to transition from
17existing IEEE 802.3 10BASE2 Ethernet and IEEE 802.5 Token Ring networks
18by providing means to reuse existing cabling.
19
20This driver handles any number of cards installed in a single system.
21They get fddi0, fddi1, etc. interface names assigned in the order of
22increasing TURBOchannel slot numbers.
23
24The board only supports DMA on the receive side.  Transmission involves
25the use of PIO.  As a result under a heavy transmission load there will
26be a significant impact on system performance.
27
28The board supports a 64-entry CAM for matching destination addresses.
29Two entries are preoccupied by the Directed Beacon and Ring Purger
30multicast addresses and the rest is used as a multicast filter.  An
31all-multi mode is also supported for LLC frames and it is used if
32requested explicitly or if the CAM overflows.  The promiscuous mode
33supports separate enables for LLC and SMT frames, but this driver
34doesn't support changing them individually.
35
36
37Known problems:
38
39None.
40
41
42To do:
43
445. MAC address change.  The card does not support changing the Media
45   Access Controller's address registers but a similar effect can be
46   achieved by adding an alias to the CAM.  There is no way to disable
47   matching against the original address though.
48
497. Queueing incoming/outgoing SMT frames in the driver if the SMT
50   receive/RMC transmit ring is full. (?)
51
528. Retrieving/reporting FDDI/SNMP stats.
53
54
55Both success and failure reports are welcome.
56
57Maciej W. Rozycki  <macro@linux-mips.org>
58