Is Artix®-7 35T FPGA Arty Evaluation Kit able to work as I2C slave?

[huangluyang]

Hi there, I wanted to use Artix®-7 35T FPGA Arty Evaluation Kit for prototyping of our ASIC, which has an I2C interface. Our ASIC is I2C slave, and our host is I2C master. Host will communicate with our ASIC through I2C bus for register programming.

My Question is that does the evaluation kit support to bring out SCL/SDA signal from FPGA to any of the socket/pin on the board? So we can connect the 2 signal to same I2C bus with out host. If it supported, will it to be done through the PMOD connector?

Thanks in advance😁

[zygot]

I2C is a proprietary interface and who knows who owns that IP now. There are of course tons of variations and implementations of the basic idea under various names ( to avoid a legal problems ) that do roughly the same thing same thing at various data rates not supported by the original specifications. The same applies to SPI. Both have ancient origins implemented with pre-FPGA technology but have have since been adopted, in one form or another, due to prevalence of the interfaces. I don't know if there even is an official specification for SPI.

The simple answer to your question is that yes you can implement a design in an Artix based board that can communicate with any of the "I2C", twin-wire, or similar interfaces that are available in any of the myriad of IC devices currently being sold. At a maximum 400 KHz data rate you can certainly use any of the Diligent Artix boards and standard PMOD as a protoype platform.

The larger question for someone developing an ASIC is defining exactly what its "I2C" interface is relative to all of the variations out there.

Edited April 26, 2022 by zygot

[huangluyang]

On 4/26/2022 at 9:34 PM, zygot said:

I2C is a proprietary interface and who knows who owns that IP now. There are of course tons of variations and implementations of the basic idea under various names ( to avoid a legal problems ) that do roughly the same thing same thing at various data rates not supported by the original specifications. The same applies to SPI. Both have ancient origins implemented with pre-FPGA technology but have have since been adopted, in one form or another, due to prevalence of the interfaces. I don't know if there even is an official specification for SPI.

The simple answer to your question is that yes you can implement a design in an Artix based board that can communicate with any of the "I2C", twin-wire, or similar interfaces that are available in any of the myriad of IC devices currently being sold. At a maximum 400 KHz data rate you can certainly use any of the Diligent Artix boards and standard PMOD as a protoype platform.

The larger question for someone developing an ASIC is defining exactly what its "I2C" interface is relative to all of the variations out there.

Dear zygot, thanks so much for your reply, yes I2C protocol/functionality isn't an issue, we've already verified that IP in previous designs. I'm just not sure whether does Digilent Artix boards hardware support the I2C requirement or not, according to your description, it sounds like that it only support maximum 400KHz data rate right? But we want to run I2C protocol at 1MHz (Fast mode plus), does it support that speed? Thanks in advance.

Edited April 28, 2022 by huangluyang

[zygot]

Artix devices of any speed grade are more than capable of running your version of I2C at 1 MHz and above data rates. Digilent rates their standard PMOD interfaces at 10 MHz, though this might be conservative for some applications. I don't see any issues that can't be addressed.

There's more to a standard, like I2C, than modes and data rates if you want to claim compatibility. As for licensing the name; that's not something I would dare comment on.