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Unread 07-03-2006, 03:34
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Re: Time available between NEW_SPI_DATA and Putdata

Quote:
Originally Posted by steven114
I'd say some testing might be in order. I've heard people say it's between a quarter and half a second, maybe more, but I can't vouch for that personally. I'd say that if you're taking more than 26.2ms then you probably need to rethink your design - I'd assume that this means you'd start dropping data packets all over the place. Probably not something you want to do.
I'm thinking it is much smaller than that. At most I would expect it to be 26.2ms. What I fear is that the master processor is setting the NEW_SPI
flag every 26.2 ms and assuming that the response will follow the setting
of NEW_SPI by some amount much less than 26.2 ms.

As you say, some testing is in order. We have an interrupt driven clock that we will use to get some numbers for the loop timings. We'll probably use the dashboard to capture the data.

I may need to check to see if we can do something like write the data to the eeprom even if we have been disabled by a code error. That brings up another question,
Can the processor detect when it is disabled by experiencing a code error?