Re: Advice on Logic Analyzer

"Vladimir Vassilevsky" <antispam_bogus@xxxxxxxxxxx> wrote in message
news:%iRMj.4152$iK6.3272@xxxxxxxxxxxxxxxxxxxxxxx
I could never understand why some people need to look at the
SPI/I2C/UART/CAN lines when it is well known that the interface outputs
exactly what you are writing into it and exactly in the way you configured
it.

Actually, there are bugs in some UARTs and similar bits of microcontroller
hardware. Additionally, just because your code is good doesn't mean the code
or hardware you're talking to is -- I've seen plenty of examples of bit-banged
I2C code that violated the spec, and since usually the person who wrote the
code isn't aware of the fact (or didn't bother to document it even if they
did), the only way you'll find out exactly what's wrong is usually to probe
the actual data lines.

The upper level protocol progress is better seen from the inside of the
machine rather then by observing the lines.

Yes, once the lowest level interface is "trustworthy," I agree.



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