TN(4) BSD Programmer's Manual TN(4)NAME
tn - TNIC-1500 ISA bus 10 Mb/s Ethernet interface
SYNOPSIS
device tn0 at isa? port 0x320 drq 3 [ flags 0x44108A04 ]
device tn0 at isa? port 0x340 drq 3 [ flags 0x44108A04 ]
device tn0 at isa? port 0x360 drq 3 [ flags 0x44108A04 ]
device tn0 at isa? port 0x300 drq 3 [ flags 0x44108A04 ]
options TNDEBUG
ifconfig tn0 [-]debug
DESCRIPTION
The tn interface provides access to a 10 Mb/s Ethernet network through
the TNIC-1500 ISA bus controller. The controller is based on the AMD
Am79C960 PCnet-ISA chip in bus master DMA mode. The cards are available
through South Coast Computing Services, Inc.
The driver provides a standard Ethernet device interface. In addition,
it will provide a diagnostic dump when the ifconfig debug command is is-
sued. If the TNDEBUG option was configured into the kernel, the command
will cause per-packet and other trace information to be printed. The
trace can be deactivated by issuing a command.
The driver discovers the irq setting, but the DMA channel number
(``drq'') must be configured in. The recommended settings of port 0x360,
drq 3, and irq 12 minimize conflicts with other standard devices. In
particular, the Adaptec 154x SCSI host adapters use drq 5, irq 11, and
0x330 by default. The TNIC-1500 uses 0x20 adjacent ports, so if you have
an Adaptec 1542 you will not be able to use 0x320 as the TNIC-1500 ad-
dress. Because ISA DMA is somewhat under designed, you will have better
luck sharing one bus with both a 1542 and a TNIC-1500 if the TNIC has a
higher (numerically lower) drq than the 1542. If this is not possible,
you should set the 1542's DMA bus timing so that it has less than 8us of
``on time''. See the Adaptec hardware manual and aha(4) for more infor-
mation.
The flags field of the configuration line is used to set DMA read and
write pulse widths and to define the LED functions. Unused portions may
be left at zero, in which case the chip's defaults are used. The low-or-
der three bytes are the LED1-3 enable masks; the low-order byte is LED1.
See the include file i386/isa/ic/am79c960.h for the bit assignments.
The high-order byte of the flags word is the DMA pulse width control,
with the first digit specifying the read pulse width and the second digit
specifying the write pulse width. The numbers are in fifty nanosecond
units with a default value of five (250ns). Reducing these values will
reduce the bus overhead, but many motherboards will not let you get away
with it.
MEDIA SELECTION
For boards that support it, media selection is performed manually by con-
figuring jumpers on the board.
ORDERING INFORMATION
For further information or to order TNIC-1500 boards, please contact
South Coast:
Fax 713.917.5005
Phone 713.917.5000
Email sales@sccsi.com
1811 Bering
Suite 100
Houston, TX 77057
SEE ALSOnetintro(4), inet(4), arp(4), The Am79c960 datasheet
HISTORY
The tn driver was written by Steve Nuchia of South Coast Computing Ser-
vices, Inc. and published in July of 1993. It became a supported part
of BSD/OS in system version 1.1. See the source file
/sys/i386/isa/if_tn.c for copyright information.
BSDI BSD/OS March 22, 1994 2