Re: Startup code

Jack Klein wrote: 
On 29 Jun 2005 01:58:33 -0700, ravikumar.n@xxxxxxxxxxxxxxxx wrote in
comp.arch.embedded:


What amazes me here, considering all the replies to the OP I see here
so far, is nobody has mentioned one of the most important reasons for
having boot code.

How do you do a complete memory test before calling the C start-up
code that requires at least some memory be working?  How do you test
the watchdog chip by forcing a reset?

Don't any of you do serious POST testing of your hardware?


I'd hardly call memory testing "one of the most important reasons for having boot code". While it is sometimes relevant to have a memory test pass, it's not a big thing. How often does memory actually fail in real life (outside of specialist systems in very harsh environments)? In particular, how often does a microcontroller's integral sram fail, or external sram or dram? If you know some statistics or web references, I'd be very interested to hear them. I think in most embedded systems, there are far more relevant hardware checks to make - the chances of having a minor memory error (major ones, like badly soldered pins, get "detected" pretty quickly) are fairly negligible in comparison.
.

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