The card is based on the Siemens/Infineon DSCC-4 (PEB-20534H) multi protocol
controller ASIC. It supports busmaster-DMA via 10 built-in DMA controllers and
descriptor handling. Thus it can work at line speeds up to 52 Mbps. All four
SCC cores and HDLC engines can be configured independently from each other.
This includes clockmode settings (external/internal RX/TX clocks, DPLL (up
to 2 Mbps) etc.) and channel coding (NRZ/NRZI/Manchester/FM0/FM1/CMI). As
you can see it is quite flexible as far as configuration is concerned. This
is why it is intended for use in PC node controller systems.
Pictures
Take a look at some commented pictures.
Additional Information
Here is a flyer I made for Weinheim/Mannheim '99.
It is only available in German, but also shows a picture and a diagram
plus some technical information.
Here is a paper which was presented during
the 16th International Packet Radio Convention at Darmstadt Technical
University on April 1st/2nd, 2000. This is an English technical paper with a lot of
background information. It should answer your remaining questions.
Even more technical information
Here is design information about the project. None of this stuff may be used
commercially! You may not sell this documentation or self-made cards built
using this stuff, not to other radio amateurs nor to anybody else without my
written permission. You may, however build these cards for your own use in
amateur radio. Contact me
if you have any questions regarding this license.
- EAGLE .sch file - schematics
- This is the schematic diagram, board revision V1.2. You need at least
EAGLE V3.55 to view it. Get a demo version at
CadSoft. Newer versions (Eagle 4.x) do not seem to be able to load the
files.
- EAGLE .brd file - board layout
- This is the board layout file, revision V1.2. You need at least
EAGLE V3.55 to view it. Get a demo version at
CadSoft. ERC and DRC will print warnings and errors, this is normal.
Press the "rats nest" button to process the ground polygons after loading.
- Notes (text,german)
- This is a text file with a lot of notes I sent to two people who wanted
to write device drivers. Sorry, German only.
- ChangeLog (text,german)
- This is a history file documenting the changes since Rev. 1.0
- Bill of Material
- Here is the BOM. Except for the DSCC-4 and the board there are only
standard parts. You can get the voltage regulator as sample from National. Other semiconductor
manufacturers sell similar parts.
Software
The reference driver was written for the Linux AX.25 network protocol stack
as defined in the paper mentioned above. Since I retired from AX.25 stack
maintenance and nobody stepped up to fill the hole this driver is only
semi-usable since the last kernel source tree I made was some 2.2.20pre
version that is pretty much out of date. No port of neither the stack nor
the driver exist for Linux-2.4, but I maintain the driver for the old
version here since I feel responsible for providing a reference for future
efforts and portage to other platforms.
Current Version: 1.85
- pciscc4.c -- Main driver source code
- pciscc4.h -- Driver definitions, macros and user interface definitions
A PC/Flexnet and Win32/Flexnet driver has been contributed by Steffen
Koehler, DH1DM and can be downloaded from
here.
Availability
The design is available - in an optimized way - from
BAYCOM. Please contact Johannes Kneip, DG3RBU for sales information.
Credits
Credits go to:
- Helmut, DG3YC for providing me with DSCC-4 samples
- Alexander, DL8AAU for cross-checking my design
- Johannes Kneip, DG3RBU for commercial support
by Jens David, DG1KJD 2002-06-02