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RE: MPC8260 ethernet BD updates - solved




The reason was the "start" function being called multiple
times. My "start" function kept re-initializing the parameter
RAM  ...

Thanks all,
Nejat

-----Original Message-----
From: Eric DeVolder [mailto:devolder@alchemysemi.com]
Sent: Wednesday, February 20, 2002 1:03 PM
To: Nejat Tek
Subject: Re: [ECOS] MPC8260 ethernet BD updates ...


isn't there a LAST bit in the BD that marks the end of the linked list?
if so, do you have this bit set, indicating that there is but the one BD
in the list? obviously you want to set this bit on the last BD in the
list...

eric

Nejat Tek wrote:

> Hello all,
>
> I am working on an ethernet driver on the mpc8260ADS-P board for ECOS
> and got it working with one Tx buffer descriptor. With multiple TxBD's,
> the CP behaves a little different than I expected:
>
> The CP checks the first TxBD and sends it when it is ready. However, it
> won't advance the TBPTR (in FCC parameter RAM) and keeps checking the
> ready bit of the first TxBD. The second, third ... and the last BD ready
> bits are set and nothing happens. When I set to the first BD ready bit
> again, the CP realizes that all BD's are ready and sends them all out.
>
> In summary :
>  -> CP polls only the first BD
>  -> If it is ready, then the CP sends out all consecutive buffers that
>     are ready ...
>
> 1) Is it supposed to work this way ? If so, I can make the driver work
> with minor modifications. But digging through the user's manual,
> (page 28-10, page 28-12 definition of TBPTR), i have the impression that
> the CP is supposed to poll the second TxBD after sending the first one.
>
> 2) If it is not supposed to work this way, what might be wrong ?
>
> Any ideas and comments appreciated ...
>
> Nejat Tek
> Software Engineer
> Delphi Communication Systems, Inc.
>
> --
> Before posting, please read the FAQ: http://sources.redhat.com/fom/ecos
> and search the list archive: http://sources.redhat.com/ml/ecos-discuss

--
Eric DeVolder
Applications Engineering
Alchemy Semiconductor, Inc.
7800 Shoal Creek Blvd., Suite 222 W
Austin, TX 78757
512.421.6285 (p)
512.421.6262 (f)
mailto:devolder@alchemysemi.com
http://www.alchemysemi.com



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