Author Topic: Auto-baud Synchronization protocol  (Read 5823 times)

dcollins

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Auto-baud Synchronization protocol
« on: April 29, 2009, 11:12:44 am »
I have a requirement to write a custom ISP program for the LPC2292 because the serial data is passed through another device that must be configured separately, and we have to program several thousand units at remote sites so it must be easy to use.

In the Phillips user manual for LPC2119/2129/2194/2292/2294, page 263 there is one paragraph that describes the auto-baud routine synchronization. It says:

1) Host should send '?'
2) LPC should reply "Synchronized<cr><lf>".
3) Host should send "Synchronized<cr><lf>".
4) LPC should reply "OK<cr><lf>".
5) Host should send it's crystal freq "10000<cr><lf>" (for 10mhz)
6) LPC should reply "OK<cr><lf>".

This works up to step 4. When the host sends "Synchronized" in step 3, the LPC replies with another "Synchronized" string, rather than "OK". If I ignore this and press on with sending the crystal freq of "10000", the LPC repeats back with "10000".

Is this a different command structure than documented? Is it a signal that there is some other problem?

Thanks very much for the help.

dcollins

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Re: Auto-baud Synchronization protocol
« Reply #1 on: April 29, 2009, 11:35:04 am »
Update:

I've just discovered when manually sending serial data that the "Synchronized" and "10000" are immediately echoed. So the messages I'm getting back is that echo, missing the "OK" (I do see the OK when manually sending).

dcollins

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Re: Auto-baud Synchronization protocol
« Reply #2 on: April 29, 2009, 05:40:19 pm »
Update:

Progress to date - I've got my program automatically Synchronizing, and now I'm playing with ISP commands manually.

Current problem: I can read the part ID and Boot code version reliably. But when testing the Read Memory I initially get what appears to be a good response of UUencoded data. But any subsequent command appears to do the Read Memory command again. I have to reset the chip and start from scratch to do anything else.

I note in another thread that you guys don't comment on ISP level issues. So perhaps I'm on my own here. I may have to nag the Field App Engineer.

Andy Ayre

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Re: Auto-baud Synchronization protocol
« Reply #3 on: May 18, 2009, 08:16:43 am »
We can offer hourly consulting for help with ISP command issues. Contact us for details.

Andy
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support at esacademy dot com