Is the I2C master controller available?

Spartan-3 USB 2.0 Modules
1

I’m just “window” shopping and I was wondering if the I2C bus on the cypress chip was available to the FPGA or even better, the PC. I understand that the I2C must be available initially for the configuration of the PLL. On the “Dragon” board available from
www.fpga4fun.com
they use a spartan 2 with a very similar cypress usb chip. The site clearly states that the I2C can be accessed and additionally the 8051 can be programmed too. Are these functions available on this board? My project is an autonomous navigating robot. I2C is widely used for interfacing sensors and other controllers.

Thanks - Justin

2

Hi Justin-

No, the I2C is not made available on the XEM3001. However, an I2C master could be programmed into the FPGA fabric. I’ve done it on past projects.

Cheers,
Jake

3

What kind of space would it take to do I2C on the FPGA? And once implemented on the FPGA how accessable are the I2C slaves by programs running on the PC side of the USB?

4

An I2C controller is pretty simple. I think there is one on OpenCores.org, but it is a bit more complicated than many applications require. Once built into the fabric, you could easily utilize the FrontPanel API to talk to your controller and thus I2C slaves.