puzzling over using boot epprom

Sawmiller

hi all,
i was just wondering if there is a simple way to write some variables to the boot epprom, for storage purposes... and then be able to access them reliably on next boot up....
for example
using a varible name for a memory location... write 2 longs to the boot epprom
then on next boot since the whole epprom is loaded into props memory, you variables are right there with the latest and greatest values...
i think it should work.. just at work right now so i cant try it.
dan
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Paul Baker

Yes you just need to figure out the correct address in the EEPROM to write it to. Fortunately its pretty simple, the address in the propeller is the same as in the EEPROM. Just use I2C routines already released in this forum to write to it. Now; variables in the propeller are initalized to 0, if you look at the memory map in the Propeller Tool you'll see this (its the yellow block). If I were doing this I would actually·use a constant, since it is expected to have a value when loaded from EEPROM, and make copious notes in the code explaining what is going on and how its value may/will change each time the propeller is booted.

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Post Edited (Paul Baker) : 6/7/2006 3:02:29 PM GMT

Sawmiller

using a constant, good idea...

hmm the address would be· @constant, to the ic2 routine...

thanks

dan

Paul Baker

Im nearly certain, you can check the compiled memory map in the Tool by filling it with something easily identifiable (say $12345678) noting it's address and comparing it with the value obtained by @constant.

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Life is one giant teacup ride.