Reorganize vendor platforms


Update amaranth.vendor namespace so that instead of:

from amaranth.vendor.lattice_ecp5 import LatticeECP5Platform

you would write:

from amaranth.vendor import LatticeECP5Platform


Vendor names are ever-changing. Xilinx was bought by AMD and the brand has been phased out. Altera was bought by Intel and the brand has been phased out. SiliconBlue has been bought by Lattice (a long time ago) and the brand has long been phased out but still remains as "SB" in SB_LUT primitive name.

In addition, we attempt to group FPGA families into a single file, like vendor.lattice_machxo2_3l that has been renamed from vendor.lattice_machxo2. This will likely include another FPGA family as soon as it becomes available.

By tying module (and file) names to brand names we create churn. Every Amaranth release so far has included renaming of both platform class names and module names. This causes additional downstream breakage and annoys designers using Amaranth.

Guide-level explanation

To target your FPGA-based project for a particular FPGA family, import the platform class corresponding to the FPGA family from amaranth.vendor, e.g.:

from amaranth.vendor import LatticeECP5Platform

Reference-level explanation

All of the modules are renamed to amaranth.vendor._internal_name.

Python allows __getattr__ to be present in modules:

$ cat >
def __getattr__(self, name):
    return f"__getattr__({name!r})"
$ python
>>> from x import abc
>>> abc

This allows us to make all the platform classes be present as-if they were defined in the amaranth.vendor modules, while retaining all of the benefits of having them in their own amaranth.vendor._internal_name module, such as lazy loading.


  • Churn.
  • A somewhat unusual loading mechanism could cause confusion.

Rationale and alternatives

Decoupling marketing/brand names from technical names is increasingly important as Amaranth evolves and supports more FPGA families. It allows us to maintain any internal hierarchy we want without it having any impact on downstream code, which solely operates on names imported from amaranth.vendor.

Prior art


Unresolved questions


Future possibilities