64K vs. 32K EEPROM test

Bobb Fwed

I want to test (run-time) if the propeller is being supplied by a 32K EEPROM or larger (64K or maybe more). Is there any way to query the EEPROM IC to get an answer? Or do I need to write to a location above $7FFF and see if I can then read the written value? Is it going to read only the bottom 15 bits of the supplied address (on a 32K), or something like that, and loop back to the beginning of the EEPROM or will it fail in some way I can detect?

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April, 2008: when I discovered the answers to all my micro-computational-botherations!

Some of my objects:
MCP3X0X ADC Driver - Programmable Schmitt inputs, frequency reading, and more!
Simple Propeller-based Database - Making life easier and more readable for all your EEPROM storage needs.
String Manipulation Library - Don't allow strings to be the bane of the Propeller, bend them to your will!
Fast Inter-Propeller Comm - Fast communication between two propellers (1.37MB/s @100MHz)!

Mike Green

There is no way to query an EEPROM to see how big it is other than by trying to use it for the capacity expected. I would try writing location $7FFF with $00, then checking to see if you've got a $00. You then write location $FFFF with $66 and see what you can read at location $7FFF. If it's $00, you've got a 64K or larger EEPROM. If it's $66, you've got a 32K EEPROM.