| Maciej W. Rozycki | 61414f5 | 2018-10-09 23:57:43 +0100 | [diff] [blame] | 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> |