At 02:46 PM 8/12/02 -0400, you wrote:


>First off, many thanks for helping me my question "How to check if an input
>gets stuck?"
>
>Now I need to do CRC check on ROM as well. I will also have to do RAM check.
>
>I will ask about CRC first.
>
>I already understand how CRC works and have a routine to calculate a 16-bit
>number's CRC.
>
>But I don't know how to apply the routine to check the program ROM and data
>ROM. (I use a small chip 12CE519.)

Real simple, Tony, you don't. If you need to meet UL1998 safety standards,
you simply cannot do it with this chip. You have to pick one that allows you
to read the program memory, either from Microchip or from someone else.

Best regards,

Spehro Pefhany --"it's the network..."            "The Journey is the reward"
speff@interlog.com             Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog  Info for designers:  http://www.speff.com
9/11 United we Stand

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