README.md

   1 ### Migen (Milkymist generator)
   2 #### A Python toolbox for building complex digital hardware
   3
   4 Despite being faster than schematics entry, hardware design with Verilog and
   5 VHDL remains tedious and inefficient for several reasons. The event-driven
   6 model introduces issues and manual coding that are unnecessary for synchronous
   7 circuits, which represent the lion's share of today's logic designs. Counter-
   8 intuitive arithmetic rules result in steeper learning curves and provide a
   9 fertile ground for subtle bugs in designs. Finally, support for procedural
  10 generation of logic (metaprogramming) through "generate" statements is very
  11 limited and restricts the ways code can be made generic, reused and organized.
  12
  13 To address those issues, we have developed the **Migen FHDL** library that
  14 replaces the event-driven paradigm with the notions of combinatorial and
  15 synchronous statements, has arithmetic rules that make integers always behave
  16 like mathematical integers, and most importantly allows the design's logic to
  17 be constructed by a Python program. This last point enables hardware designers
  18 to take advantage of the richness of the Python language - object oriented
  19 programming, function parameters, generators, operator overloading, libraries,
  20 etc. - to build well organized, reusable and elegant designs.
  21
  22 Other Migen libraries are built on FHDL and provide various tools such as a
  23 system-on-chip interconnect infrastructure, a dataflow programming system, a
  24 more traditional high-level synthesizer that compiles Python routines into
  25 state machines with datapaths, and a simulator that allows test benches to be
  26 written in Python.
  27
  28 See the doc/ folder for more technical information.
  29
  30 Migen is designed for Python 3.3. Note that Migen is **not** spelled MiGen.
  31
  32 #### Quick Links
  33
  34 Code repository:
  35 https://github.com/m-labs/migen
  36
  37 System-on-chip design based on Migen:
  38 https://github.com/m-labs/misoc
  39
  40 Online documentation:
  41 http://m-labs.hk/gateware.html
  42
  43 #### Quick intro
  44 ```python
  45 from migen.fhdl.std import *
  46 from mibuild.platforms import m1
  47 plat = m1.Platform()
  48 led = plat.request("user_led")
  49 m = Module()
  50 counter = Signal(26)
  51 m.comb += led.eq(counter[25])
  52 m.sync += counter.eq(counter + 1)
  53 plat.build_cmdline(m)
  54 ```
  55
  56 #### License
  57 Migen is released under the very permissive two-clause BSD license. Under the
  58 terms of this license, you are authorized to use Migen for closed-source
  59 proprietary designs.
  60 Even though we do not require you to do so, those things are awesome, so please
  61 do them if possible:
  62 * tell us that you are using Migen
  63 * put the Migen logo (doc/migen_logo.svg) on the page of a product using it,
  64   with a link to http://m-labs.hk
  65 * cite Migen in publications related to research it has helped
  66 * send us feedback and suggestions for improvements
  67 * send us bug reports when something goes wrong
  68 * send us the modifications and improvements you have done to Migen. The use
  69    of "git format-patch" is recommended. If your submission is large and
  70    complex and/or you are not sure how to proceed, feel free to discuss it on
  71    the mailing list or IRC (#m-labs on Freenode) beforehand.
  72
  73 See LICENSE file for full copyright and license info. You can contact us on the
  74 public mailing list devel [AT] lists.m-labs.hk.
  75
  76   "Electricity! It's like magic!"