> That is true however with embedded systems the question  is
> if the ROM can be proven defective then what?  The answer depends
> on the application. In John's original post he was making a point that
> the ROM test routine for something like the 17Cxxx parts could be
> placed in a more reliable ROM than the application is stored in.

In some situations, the device may be designed so that if the checksum
on the flash fails, it will still provide some minimal degree of func-
tionality including the ability to signal the failure and/or request and
receive new code (e.g. if the device has a modem it could call up a
central system where the code was kept).

Especially in the context of flash-based systems built with surface-mount
parts, including a CRC/bootloader in ROM may make the difference between
having to unsolder/resolder parts (MAJOR bummer) and simply having to hook
up a programming jumper or run special computer software (much easier).
In general, though, unless something useful can be done in case of a CRC
failure there isn't much point in even having the check.