Newbie B2 Questions


Hi all, I’m an iCE40 newbie and have a few questions! I’ve just bought a B2 and I want to interface it to a UM245R. This can supply both 5V and 3V3 VCC to the B2. So, should I connect the 5V from the UM245R to the B2, or the 3V3? Or is this not possible, and I should power both the B2 and the UM245R from USB cables?

Also, are pins 14-17 connected directly to the 4Mbit SPI flash, and so should I avoid using these pins?

Many thanks & hope you all have a happy festive season.


I recommend only connecting the 5v power. The B2 will then generate its own 3.3v power. You can use pins 14-17, but you need to be careful not to drive them until after the FPGA is configured.


Thanks for the information, Luke. I generated my first B2 bitstream with IceStorm last night while waiting for the B2 to arrive, so I should be able to breadboard it all when it arrives.
Cheers, Warren