ECP5 FOSS ULX3S Blinky

This is a simple, sample project that blinks some LEDs on the ULX3S ECP5 FPGA board. It only uses Open Source software to accomplish this goal, from Verilog to bitstream.

Prerequisites

• yosys (at least git revision 5387ccb041f4acafc96c7b3fcf8db04dddfb8ab5)
• nextpnr (at least git revision 31c199f674a0c2cc381eb09510aaa8ad8d5ae3fd, with ECP5 support enabled)
• openocd with 4f134c755d7209a8eb1c4460e09f5c68622ef0bd cherrypicked or merged

Usage

Clone this repository. Either use it as a starting point for your project, or just copy the files over.

By default, we target the ULX3S with an LFE5U-85F. If you target a different chip, you will have to edit the PART_* variables in the Makefile, and, to use OpenOCD for flashing, you will have to edit the idcode in ulx3s/openocd.cfg.

To build the blinky, run make flash.

Runtime options for Makefile

• YOSYS - path to Yosys binary. By default, yosys in path.
• NEXTPNR - path to nextpnr-ecp5 binary. By default, nextpnr-ecp5 in path.
• ECPPACK - path to ecppack from prjtrellis. By default, ecppack in path.
• TRELLIS - path to prjtrellis installation directory. By default, /usr/share/terllis.

License

The blinky code comes from nextpnr and is licensed under the ISC License.

The Makefile, LPF constraint file, OpenOCD script, title photograph and this README are under CC0.