This gives particularly pathological results on IO buffers, like:
connect \D_OUT_0 \user_led_0_user_led_0__o
Since subfragment signals are name-prefixed because this works well
for signals propagated upwards across hierarchy, this is never
desirable for instances.
This is useful when most attributes in a large composite resource
are the same, but a few signals are different, and also when building
abstractions around resources.
Fixes#128.
This primarily fixes the problem with source location precision in
Module (which used to trace locations from __exit__ of the context
managers, by which point everything interesting has been lost), but
also improves memory port and control inserter source locations.
On the sample of examples/basic/*.py, the only incorrectly inferred
remaining location is clk pointing to hdl/mem.py:166.
This effectively reverts and reimplements half of commit 82903e49.
I was confused and did not realize that RTLIL does, in fact, have
attributes on switches.
After this commit, processes no longer have any source locations.
This is semantically fine, as the processes we emit are purely
artificial (because of LHS grouping), but I have not checked how
downstream tooling handles this.
Right now an array is expected in any _opts overrides, and if it is
actually a string (because it is passed via an environment variable,
usually), awkwardness results as each character is joined with ` `.
Fixes#130.
This is useful for two reasons:
1. nMigen can provide better error messages than the platform and
do it earlier in the build pipeline.
2. Many platforms handle diffpairs by only constraining the P pin;
the N pin is completely ignored. If this is undetected,
downstream users (human or software) can rely on this
information assuming it is correct and introduce more errors.
(Of course, this will not catch every mistake, but the most
common is a copy-paste issue, and that will handle it.)
Fixes#124.
In compat.fhdl.module, we already default to "sync" as the default
clocked domain. Using "sys" in memories only would be inconsistent
and result in more bugs.
According to RTLIL semantics (that was undocumented before today),
the only purpose of `sync always` is to enable inference of latches,
because there is no other way to express them in terms of RTLIL
processes without ending up with a combinatorial loop. But, nMigen
specifically avoids latches, so this is not necessary.
This change results in major improvements in Verilog readability.
See also #98.
