Hi,
I still don´t get it. Sorry.
Is it your initial aim to implement I2C --> and you (think to) need a non volatile SRAM for this?
If so then: A standard I2C implementation does not need NVRAM, it needs standard RAM or at least FFs. But maybe your application needs some NVRAM to store data, we don´t know.
Or does your application need to use an external non volatile SRAM --> and you need to implement I2C for this?
If this is the case there are some alternatives:
* NVRAM with SPI
* NVRAM with parallel bus
* battery (backup) powering the FPGA
..but I2C implementation is nothing special for an FPGA.
Klaus