File:       COBRAXXXX-FAQ_en.txt
Location:   uClinux-dist/Documentation/COBRAXXXX/en/
            and COBRAXXXX-CD/documentation/boards/
Author:     Heiko Degenhardt (linux@sentec-elektronik.de)
Contents:   Frequently asked questions about the board.
Version:    v01.00
Date:       Wed Mar 24 17:59:40 CET 2004
License:    This document is under the GNU GPL
            (see uClinux-dist/COPYING)
______________________________________________________________________

CHANGES

040324  v01.00 Creation
        (new file, because it is for both boards now)
        (hede)
______________________________________________________________________

GENERAL

Q: What does "COBRA5272" or "COBRA5282" mean?
A: COBRA stands for "COldfire Board for Rapid Applications". The 5272
   shows that the board is based on Motorola's ColdFire 5272. The
   COBRA5282 is based on the MCF5282.

Q: Where can I order the boards? Is there a web site?
A: You can order the boards via the German distributor ELEKTRONIKLADEN.
   Their web sites for the boards are
   http://www.elektronikladen.de/cobra5272.html and
   http://www.elektronikladen.de/cobra5282.html.
   The home page of the boards is at
   http://www.sentec-elektronik.de/cobra/.

Q: Ok, now I have the board. What are the first steps I should do
   to get a running image?
A: Now that you have downloaded the uClinux-dist sources please read 
   ./Documentation/COBRAXXXX/en/COBRAXXXX-Getting-started_en.txt
   to get started. If you obtained the COBRAXXXX-CD, you will find 
   all related pdf files in /documentation/boards/.

COMMUNICATION

Q: What cable have I to use for communicating via the serial port?
A: You can use a "normal" serial cable, not a so called "null modem
   cable".

Q: What are the standard values for the communication parameters?
A: Serial Port: 19200 Baud, 8n1
   Server IP:   192.168.100.1
   Client IP:   192.168.100.2
   Netmask:     255.255.255.0
   Gateway IP:  0.0.0.0
   Ethernet:    00:00:00:00:00:01 
(The default MAC address for the COBRA5282 is 00:CF:52:82:CF:01).

Q: How can I configure the parameters for the commands that are
   executed on kernel start up?
A: At start-up of the uClinux kernel the commands of the file
   uClinux-dist/vendors/senTec/romfs/etc/rc get executed.
   Here you can configure for instance the IP address, the netmask,
   if you want to mount a directory via NFS, and if so, which
   directory gets mounted and so on.
   (HINT: To get a detailed description you should look into the
   manual pages of the commands, eg. "man ifconfig").

ERRORS/PROBLEMS

Q: The board always does a reset. What can I do?
A: Here are some things to check:
   a) Increase the value of the current clamp:
   The power supply should give around 500mA at 6V (if you have a
   starter kit with a linear voltage regulator you can try to
   increase the voltage to around 7.5V).

   b) Measure the voltage:
   On the starterkit board you find opposite to the bdm connector
   a row of LED's (D3..D10). On the left site of it there is a
   edge connector. There you have plus on the one site, and ground
   on the other. The voltage there should be >3.15V.
   On the COBRA5282 board, near the breadbord area, you find
   2 rows with 4 pins each. They are labeled "GND" and "+3.3V".
   Between 2 of their pins you should measure a voltage >3.15V.

Q: "make" gives an error about a missing reference to
   "del_mtd_partitions"?
A: You must set CONFIG_MTD_PARTITIONS in the kernel config!

Q: I don't have a BDM-Adaptper. Where can I get one?
A: You can look for it for instance at http://www.pemicro.com or
   http://www.cybertec.com.au. Make sure to use a
   "Shielded ColdFire BDM Adapter, 3.3V".

Q: After "make dep" or "make" there are many messages scrolling out
   of the terminal window. How is it possible to read them?
A: You can for instance "pipe" them into the program "tee" that
   writes them into a file, eg. "errs". To do that, just type:
   "make 2>&1 | tee errs".

Q: The tftp download from dBUG doesn't work, gives errors or
   simply stops, but my cabling is correct. What can I do?
A: There seem to be errors in the dBUG source code that make
   it less tolerant against errors concerning problems with
   the network interfaces. As far as we can tell the download
   works more stable if you give the file name on the command
   line, e.g. "dn image.bin".
   You should set the network speed to 10MBit on the COBRA5272
   and to 100MBit half duplex on the COBRA5282. To do that
   you can for instance use mii-tool on a Linux host.
   There seem to be no problems if you use a switch or hub
   to connect the board with your PC.

Only for COBRA5272:
Q: I want to use the external bus for my own periphals. With the
   oscilloscope I can see, that the external chipselects are
   "floating", and so my periphals cannot work. What can I do?
A: The buffers IC 0201 - IC 0209 (see Schematic p. 3) are selected
   with the same chipselects. When the buffers are disabled, the 
   level of all external signal (includig the chipselects) are
   falling to Ground. To avoid this, the used chipselects can
   be pulled up (eg. with 4,7k) to 3,3V.


FEEDBACK

If you find errors, or have some tips or questions concerning this
FAQ, please send an email to linux@sentec-elektronik.de. You'll
easily find out that I'm not a native English speaker, so feedback
is really welcome!

______________________________________________________________________
(c) 2004, senTec Elektronik Gmbh, Heiko Degenhardt

