Tuesday, November 26, 2013

Soft error

So you're in your Lab integrating your Software Module on a brand new System.

In Embedded Engineering sometimes SW can be useful to debug/validate new
hardware components and people from the hardware division knows it
very well :-)

Using your 'old and validated' protocol on a simple RS-232 it seems that
data coming from sensors are 'slow'.

Hardware division says... 'It's a Software Problem' :-) 

Ok, let's see it.

You connect the JTAG on the Micro, launch your debugger, put a break point
in your 'old and validated' protocol.. dump the buffer coming from
the RX channel and... hey wait...

Data coming from sensors should be 0xAFCED0... but periodically I see....
0xAECED0.... it seems there is a bit-flip and the CheckSum routine is 
throwing away data...  

I simply move the cable connector and... now data arriving at the right frequency..

'Software problem'... uh? :-)

Perhaps you mean 'Soft', not 'Software'...  http://en.wikipedia.org/wiki/Soft_error

Don't Trust Hardware :-)

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