eeprom for propeller

stef

Hi

Just a smal question.

I normaly use an eeprom 24LC256.

I now got my hands on a lot 24LC128. I know they are saller in size.

Can I also use them to load the propeller Spin program in it.

Stefan

pullmoll

stef said...
Can I also use them to load the propeller Spin program in it.

I don't think you can use them as device at address 0, i.e. for booting the propeller, because the boot loader expects to read 32KB and I don't know what happens when you try to read beyond the end of an EEPROM. It should be possible to have additional chips on higher addresses and read/write them with an I2C object.

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Pullmoll's Propeller Projects

Dave Hein

I am guessing that the 24LC128 will ignore the 15th address bit, so the boot loader should·read the same 16K image into both halves of the 32K RAM space.· This will work OK as long as the program fits in 16K, and it doesn't assume that all of the memory is zeroed out after the end of the program.· Some programs assume that VAR variables have an initial value of zero.· However, if the program + VAR space fits in 16K there is no problem.

However, there will be a problem with the Spin tool writing the EEPROM.· It will write the first 16K OK, but then the second 16K will overwrite the first 16K.· You will need to write the 16K EEPROMs yourself.

Dave

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