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61414f5e MR |
1 | Notes on the DEC FDDIcontroller 700 (DEFZA-xx) driver v.1.1.4. |
2 | ||
3 | ||
4 | DEC FDDIcontroller 700 is DEC's first-generation TURBOchannel FDDI | |
5 | network card, designed in 1990 specifically for the DECstation 5000 | |
6 | model 200 workstation. The board is a single attachment station and | |
7 | it was manufactured in two variations, both of which are supported. | |
8 | ||
9 | First is the SAS MMF DEFZA-AA option, the original design implementing | |
10 | the standard MMF-PMD, however with a pair of ST connectors rather than | |
11 | the usual MIC connector. The other one is the SAS ThinWire/STP DEFZA-CA | |
12 | option, denoted 700-C, with the network medium selectable by a switch | |
13 | between the DEC proprietary ThinWire-PMD using a BNC connector and the | |
14 | standard STP-PMD using a DE-9F connector. This option can interface to | |
15 | a DECconcentrator 500 device and, in the case of the STP-PMD, also other | |
16 | FDDI equipment and was designed to make it easier to transition from | |
17 | existing IEEE 802.3 10BASE2 Ethernet and IEEE 802.5 Token Ring networks | |
18 | by providing means to reuse existing cabling. | |
19 | ||
20 | This driver handles any number of cards installed in a single system. | |
21 | They get fddi0, fddi1, etc. interface names assigned in the order of | |
22 | increasing TURBOchannel slot numbers. | |
23 | ||
24 | The board only supports DMA on the receive side. Transmission involves | |
25 | the use of PIO. As a result under a heavy transmission load there will | |
26 | be a significant impact on system performance. | |
27 | ||
28 | The board supports a 64-entry CAM for matching destination addresses. | |
29 | Two entries are preoccupied by the Directed Beacon and Ring Purger | |
30 | multicast addresses and the rest is used as a multicast filter. An | |
31 | all-multi mode is also supported for LLC frames and it is used if | |
32 | requested explicitly or if the CAM overflows. The promiscuous mode | |
33 | supports separate enables for LLC and SMT frames, but this driver | |
34 | doesn't support changing them individually. | |
35 | ||
36 | ||
37 | Known problems: | |
38 | ||
39 | None. | |
40 | ||
41 | ||
42 | To do: | |
43 | ||
44 | 5. 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 | ||
49 | 7. Queueing incoming/outgoing SMT frames in the driver if the SMT | |
50 | receive/RMC transmit ring is full. (?) | |
51 | ||
52 | 8. Retrieving/reporting FDDI/SNMP stats. | |
53 | ||
54 | ||
55 | Both success and failure reports are welcome. | |
56 | ||
57 | Maciej W. Rozycki <macro@linux-mips.org> |