Lattice iCE40 is documented [1] and it has fully open source development tools [2], [3] [1] https://github.com/cliffordwolf/icestorm https://github.com/cliffor

Lattice iCE40 is documented [1] and it has fully open source development tools [2], [3] [1] https://github.com/cliffordwolf/icestorm https://github.com/cliffordwolf/icestorm [2] http://www.clifford.at/yosys/ http://www.clifford.at/yosys/ [3] https://github.com/cseed/arachne-pnr https://github.com/cseed/arachne-pnr