Unable to write to 64K EEPROM Upper Half

william chan

Help !

When I write to an address higher than 32K in a 24C512 eeprom,
like below,

OBJ
i2c : "basic_i2c_driver"

eeprom.WriteLong(i2c#bootpin,i2c#eeprom,32768,data)

it actually overwrites the Propeller's own program.
This happens everytime.
Then the Propeller cannot be reset since it's own program is corrupted.

What could be wrong?

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Mike Green

Are you sure you have a 24C512 EEPROM? What you wrote should work with a 24C512.

william chan

I just bought it from Farnell.
Everything else works with this eeprom.

Have you tested the basic_i2c_driver with this eeprom before?

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hippy

You can try writing to $FFFF and similar top-32KB addresses and checking what is written there and the corresponding lower-32KB addresses. Any overwriting of the top end of the lower-32KB should have less impact on the program which is being bootloaded.

Mike Green

The basic_i2c_driver has been tested on a Propeller Protoboard which uses an Atmel 24C512.
There's nothing in the code that would cause addresses to wraparound at 32K. The only mechanism for
what you're reporting would be a substitution of a 32K byte EEPROM for the expected 64K byte EEPROM.

william chan

Sorry Mike and everyone else.
It was a wrong chip that was plugged in.
The basic_i2c_driver now works with the correct 24LC512 chip.

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www.fd.com.my
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