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Re: F21c in fab


I am offering a suggestion for the on-chip ROM on the F21 to allow
booting a system without an external EPROM.

32K byte serial EEPROMs are available that require only 2 I/O lines
clk+data) to be accessed. 

Could the boot ROM include routines to read user code from here into
RAM for execution. Also, some method would be needed to download via
a serial port directly into RAM or the serial EEPROM.

Actually, this is not really a question, more of a plea.

I'd be more than happy to implement the code necessary once I get some
idea of the size of the on-chip ROM available. I guess that the code
would only require a few hundred bytes, although 1K would be more
reasonable to allow for improved serial drivers etc.

I've used this method before for OTP style micros with external RAM and
it's still ok to use with an external EPROM just so that user code can
be made non-volatile and still changed easily.

-- 
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