After laying on my nightstand for 3 weeks (during which my BlackIce-II board got all my attention), it's time to get a minimal design going.
The Upduino documentation on GitHub is a Word file that describes how to create a LED blink design with the Lattice iCECube2 software and how to program it with the Lattice Diamond programmer. I don't have those, but I decided to try if it works with Project IceStorm.
Of course, it does.
After the usual amount of struggling with command line options (forgetting to use `sudo` didn't help either), it was able to get a blinking LED going. The results can be found here: https://github.com/tomverbeure/upduino/tree/master/blink
Check out the Makefile for the right combination of command line parameters for the different tools.
- The 3-color high-intensity LEDs are really very bright
- Programming the SPI flash with the bitstream takes quite a bit longer than for the BlackIce-II even though the bitstream is 30% smaller. I think that's because the FTDI chip is used to transmit bit-banged signals over USB. The BlackIce-II is using DFU mode instead, where the bytes of the STM32 on-board flash are transmitted as bytes.
- The Upduino comes with no design loaded in its flash. As long as you don't successfully upload a design, you have no idea whether the board is fully functional. It would have been useful for the SPI flash to be preprogrammed with a design that blinks the LED.
- As soon as the FPGA has been successfully configured, the green CDONE LED goes up. It's way too bright for a status LED that will be on all the time.
- Last but not least: there something about my board that makes it pretty hot, even when not design is load at all! I think it's somewhere around the FTDI chip. This might be an issue with my board.