From ba646ac8c47ab74c5509855e45be611b039ad083 Mon Sep 17 00:00:00 2001 From: Eddie Hung Date: Thu, 27 Dec 2018 23:49:16 -0800 Subject: [PATCH] Update README.md --- README.md | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/README.md b/README.md index 5b79d1fb..5733a40d 100644 --- a/README.md +++ b/README.md @@ -1,6 +1,19 @@ nextpnr -- a portable FPGA place and route tool =============================================== +*** +### NB: This nextpnr-xc7 branch is *unofficial*, *very* proof-of-concept, *very* experimental, *very* unoptimised, and is provided with *no support whatsoever*. Use at your own risk! +#### It leverages a [torc](https://github.com/torc-isi/torc) fork with minimal changes (those necessary to support building on later versions of gcc) to target XDL-compatible devices. +### Note that torc is licensed under GPLv3 which differs from nextpnr's ISC license, thus please respect the limitations imposed by both licenses. +Currently, only LUT1-6, IOB, BUFGCTRL, MMCME2_ADV are supported for xc7z020 and xc7vx680t (but trivial to add others). +The following example shell scripts are available: +* blinky.sh -- generates blinky.bit that flashes (with a delay) the 4 LEDs on a ZYBO Z7 +* blinky_sim.sh -- post place-and-route simulation, without any delays (requires [GHDL](https://github.com/ghdl/ghdl)) +* picorv32.sh -- just places-and-routes picorv32.ncd (no testbench) +* attosoc.sh -- generates attosoc.bit of a self-stimulating picorv32 device that displays (with a delay) prime numbers to the LEDs -- when testing on hardware, consider using a PLL (MMCM) to meet timing +* attosoc_sim.sh -- post place-and-route simulation of a self-stimulating picorv32 device, without any delays (requires [GHDL](https://github.com/ghdl/ghdl)) +*** + nextpnr aims to be a vendor neutral, timing driven, FOSS FPGA place and route tool.