68300

Hello All,
         I am facing a very curious problem related to expansion of 
memory. I used to access 1 MB of RAM using 4 chip selects (CS0, CS1, CS2, 
CS10).
       I got a ciruit from Mr Liubo, which I am using to access 4 MB of 
RAM using the 4 chip selects along with SIZ1, SIZ0, A0, RW.

         The circuit works fine but I added a header to the circuit which 
connects to a daughter board. The problem I face is that as soon as I 
connect a cable (even without the daughter board connected at the other 
end) the system fails to initialize.
         Pull out the cable and the board initializes, and if the cable 
length is less than 5 cm the board initializes.

        The signals going to the header are D8-D15, A1-A6, PORTF1, RW, 
RESET, AVEC(I/O), DSACK1(I/O) and CS4.

   When I connect a debugger I get an error that there is an error 
writing to the registers initializing PortE. Siz0 and Siz1 are part of 
PortE, so that is probably the problem.
 
    Does anybody have any suggestions.


Thanks & Regards,
Philip Jones,
Engineer,
R&D Department,
ID Technologies. (A division of mark elektriks)
============================================================
B1/1, Sai Sahawas Apt.,  | Phone: +91-20-4003315, 4007158
Oppo. Corporation Bank,  | TeleFax: +91-20-5410479
Maharshi Karvenagar,     | Email: development@...
Hingne (Bk),             | www.markelektriks.com
Pune - 411052. India.    |
============================================================

Hello Mr Jones

Do you have the right resistors (pull up, pull down) connected to the
lines DO-D11, MODCLK,BKTP
-> This lines are used for basic up initialization. 

For example D8: 
with Pull up => don't remember, but not a parallel interface :-)
Pull down => parallel interface PORTE

Probably you get with the connected cable to much noise on the line. I
would try it with all the resistors connected 
(of course the right ones :-); pull up or pull down).

Regards

Ivo

-----------------------------------------------------
Ivo Strebel
SCHILLER AG, Altgasse 68, CH-6341 Baar
Phone +41 41 766 42 42 / Fax +41 41 761 08 80
Direct Phone / Voice Box +41 41 766 43 55
Ivo.Strebel@...  / www.schiller.ch
>>> development@... 09/02/04 6:44 AM >>>
Hello All,
         I am facing a very curious problem related to expansion of 
memory. I used to access 1 MB of RAM using 4 chip selects (CS0, CS1,
CS2, 
CS10).
       I got a ciruit from Mr Liubo, which I am using to access 4 MB of 
RAM using the 4 chip selects along with SIZ1, SIZ0, A0, RW.

         The circuit works fine but I added a header to the circuit
which 
connects to a daughter board. The problem I face is that as soon as I 
connect a cable (even without the daughter board connected at the other 
end) the system fails to initialize.
         Pull out the cable and the board initializes, and if the cable 
length is less than 5 cm the board initializes.

        The signals going to the header are D8-D15, A1-A6, PORTF1, RW, 
RESET, AVEC(I/O), DSACK1(I/O) and CS4.

   When I connect a debugger I get an error that there is an error 
writing to the registers initializing PortE. Siz0 and Siz1 are part of 
PortE, so that is probably the problem.
 
    Does anybody have any suggestions.


Thanks & Regards,
Philip Jones,
Engineer,
R&D Department,
ID Technologies. (A division of mark elektriks)
============================================================
B1/1, Sai Sahawas Apt.,  | Phone: +91-20-4003315, 4007158
Oppo. Corporation Bank,  | TeleFax: +91-20-5410479
Maharshi Karvenagar,     | Email: development@...
Hingne (Bk),             | www.markelektriks.com
Pune - 411052. India.    |
============================================================





 
Yahoo! Groups Links

development,\ufffd\ufffd\ufffd�\ufffd

	Maybe you can have a look at the DSACK signal,I remember that one
time I tied DSACK line to the wrong level(CPU can't end the memory write
and read) and the system can not boot.

======= 2004-09-02 10:14:00 \ufffd\ufffd\ufffd\ufffd\ufffd\ufffd\ufffd\ufffd\ufffd\ufffd\u0434\ufffd\ufffd\ufffd\ufffd=======

>Hello All,
>         I am facing a very curious problem related to expansion of 
>memory. I used to access 1 MB of RAM using 4 chip selects (CS0, CS1, CS2, 
>CS10).
>       I got a ciruit from Mr Liubo, which I am using to access 4 MB of 
>RAM using the 4 chip selects along with SIZ1, SIZ0, A0, RW.
>
>         The circuit works fine but I added a header to the circuit which 
>connects to a daughter board. The problem I face is that as soon as I 
>connect a cable (even without the daughter board connected at the other 
>end) the system fails to initialize.
>         Pull out the cable and the board initializes, and if the cable 
>length is less than 5 cm the board initializes.
>
>        The signals going to the header are D8-D15, A1-A6, PORTF1, RW, 
>RESET, AVEC(I/O), DSACK1(I/O) and CS4.
>
>   When I connect a debugger I get an error that there is an error 
>writing to the registers initializing PortE. Siz0 and Siz1 are part of 
>PortE, so that is probably the problem.
> 
>    Does anybody have any suggestions.
>
>
>Thanks & Regards,
>Philip Jones,
>Engineer,
>R&D Department,
>ID Technologies. (A division of mark elektriks)
>============================================================
>B1/1, Sai Sahawas Apt.,  | Phone: +91-20-4003315, 4007158
>Oppo. Corporation Bank,  | TeleFax: +91-20-5410479
>Maharshi Karvenagar,     | Email: development@...
>Hingne (Bk),             | www.markelektriks.com
>Pune - 411052. India.    |
>============================================================
>
>
>
>
>
> 
>Yahoo! Groups Links
>
>
>
> 

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\ufffd\ufffd
 
				 
\ufffd\ufffd\ufffd\ufffd\ufffd\ufffd\ufffd\ufffd\ufffd\ufffd\ufffd\ufffd\ufffd\ufffd\ufffd\ufffdliubo
\ufffd\ufffd\ufffd\ufffd\ufffd\ufffd\ufffd\ufffd\ufffd\ufffd\ufffd\ufffd\ufffd\ufffd\ufffd\ufffdboliu@...
\ufffd\ufffd\ufffd\ufffd\ufffd\ufffd\ufffd\ufffd\ufffd\ufffd\ufffd\ufffd\ufffd\ufffd\ufffd\ufffd\ufffd\ufffd\ufffd\ufffd2004-09-03