Question Detail
I am having trouble with a new FT 5000 design. I am getting write errors when I try to program code onto the ONSemi CAT24C512 over the network.
Solution
The FT5000 does not support the ONSemi CAT24C512 EEPROM, because the CAT24C512 responds to messages that use the I2C one-byte addressing mode. Typically the I2C one-byte addressing mode is reserved for smaller EEPROM memory sizes such as 2KB parts. The FT5000 Neuron firmware does not expect the CAT24C512 to respond to the I2C one-byte addressing method and the Neuron firmware becomes confused when the CAT24C512 responds to the I2C one-byte addressed message.
In general, once the FT5000 powers up it goes through a discovery process to find any blank, writable EEPROMs that are connected to the FT5000. The discovery process will check if any EEPROM devices respond to the I2C one-byte address method first, and if the FT5000 does not find any EEPROMs, it will try to discover any EEPROM devices that respond to the I2C two-byte addressing mode.
Initially the FT5000 discovers the CAT24C512 and loads the basic 2K image onto the CAT24C512 using the I2C two-byte addressing mode.
The next time the FT5000 resets, the FT5000 discovers the CAT24C512 when it responds to the FT5000 read of the "signature" using the I2C one-byte addressing method. The FT5000 is not expecting the CAT24C512 to respond to the I2C one-byte addressing method, which causes the error.
The only ON Semiconductor 12C EEPROM supported by the FT5000 chips is CAT24C16.
Related Products
- FT 5000
- Neuron 5000
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