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