MachXO2 Architecture Example

This contains a simple example of running nextpnr-machxo2:

simple.sh generates JSON output (pnrblinky.json) of a classic blinky example from blinky.v.
simtest.sh will use yosys to generate a Verilog file from pnrblinky.json, called pnrblinky.v. It will then and compare pnrblinky.v's simulation behavior to the original verilog file (blinky.v) using the iverilog compiler and vvp runtime. This is known as post-place-and-route simulation.

As nextpnr-machxo2 is developed the contents simple.sh and simtest.sh are subject to change.

Environment Variables For `simple.sh` And `simtest.sh`

YOSYS- Set to the location of the yosys binary to test. Defaults to the yosys on the path. You may want to set this to a yosys binary in your source tree if doing development.
NEXTPNR- Set to the location of the nextpnr-machxo2 binary to test. Defaults to the nextpnr-machxo2 binary at the root of the nextpnr source tree. This should be set, for instance, if doing an out-of-tree build of nextpnr-machxo2.
CELLS_SIM- Set to the location of machxo2/cells_sim.v simulation models. Defaults to whatever yosys-config associated with the above YOSYS binary returns. You may want to set this to /path/to/yosys/src/share/machxo2/cells_sim.v if doing development; yosys-config cannot find these "before-installation" simulation models.