Erasing blocks of EPROM

Steel

Is there a way to bulk-erase eeprom contents on BS2?

I am afraid of the program memory it will take to do "WRITE 0,FF,FF,FF...." throughout the eeprom...

I am not interested in removing the program that I write to the EEPROM.· I am saving a large amount of·information from 000 to 400 that I want the user to be able to Erase and overwrite at given times.

·

Jon Williams

You can always use a loop:

· FOR eeAddr = StartAddr TO EndAddr
··· WRITE eeAddr,·$FF
· NEXT


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Jon Williams
Applications Engineer, Parallax

Steel

oh yeah...loops...

lol

thanks, Jon.

allanlane5

And, as always, note you can only write to each EEPROM location a million times or so.

This is not a problem if writing 5 times a day. But if writing once every millisecond, you can wear out a location in a week.

Just be careful.

Tracy Allen

Also, it might be possible to simply mark it as having been erased, without actually erasiing it. I don't know the nature of this data, but if it is a sequential file, pointers to the beginning and end can be stored. A clock battery backed ram is a great place to store such pointers. If the data has a block structure or fixed fields, it may be possible to set one bit somewhere to mark the block as erased. Finally, if you use external eeprom instead of the Stamp's own eeprom, then you will in fact have access to the block erase commands that can zap 32 or more bytes at a pop.

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Tracy Allen
www.emesystems.com