This example is for the [Lattice iCE40HX-8K Breakout Board](http://www.latticesemi.com/Products/DevelopmentBoardsAndKits/iCE40HX8KBreakoutBoard.aspx). An image of this board is shown below; ![img/iCE40HX8K-breakout-revA.png] This board can be purchased for ~$USD 49 directly from Lattice and is supported by the IceStorm [`iceprog`](https://github.com/cliffordwolf/icestorm/tree/master/iceprog) tool. # Using the example ## Before Starting Before starting make sure that your board is configured for `CRAM Programming` mode. This requires removing jumper `J7` and putting the pair of jumpers on `J6` to be parallel to the text on the board. This is shown in **Figure 5** of the [iCE40HX-8K Breakout Board User Guide](http://www.latticesemi.com/view_document?document_id=50373). which is also reproduced below; ![img/cram-programming-config.png] Once your board is ready, you should follow the setup instructions at the [top level](../../../README.md). You should make sure you have the following tools installed; * Yosys * arachne-pnr * icestorm tools (like icepack and iceprog) * riscv toolchain * sbt ## Building You should be able to just type `make compile` and get output similar to this; ``` ... place time 10.14s route... pass 1, 15 shared. pass 2, 4 shared. pass 3, 1 shared. pass 4, 0 shared. After routing: span_4 4406 / 29696 span_12 951 / 5632 route time 9.12s write_txt bin/toplevel.asc... icepack bin/toplevel.asc bin/toplevel.bin ``` The process should take around 30 seconds on a reasonable fast computer. ## Programming After building you should be able to run `make prog`. You may need to run `make sudo-prog` if root is needed to access your USB devices. You should get output like the following; ``` iceprog -S bin/toplevel.bin init.. cdone: high reset.. cdone: low programming.. cdone: high Bye. ``` After programming the LEDs at the top of the board should start flashing in an interesting pattern. ## Connect After programming you should be able to connect to the serial port and have the output echoed back to you. On Linux you can do this using a command like `screen /dev/ttyUSB1`. Then as you type you should get back the same characters.