From 08aaac9a41eccde9cbb6df28573aa682a3c1ecc1 Mon Sep 17 00:00:00 2001 From: Wanda Date: Mon, 15 Apr 2024 19:26:27 +0200 Subject: [PATCH] docs/guide: remove warning about lack of combinational loop detection. --- docs/guide.rst | 8 -------- 1 file changed, 8 deletions(-) diff --git a/docs/guide.rst b/docs/guide.rst index d11e589..0a8daf8 100644 --- a/docs/guide.rst +++ b/docs/guide.rst @@ -1250,14 +1250,6 @@ Whenever the signals ``en`` or ``b`` change, the signal ``a`` changes as well. I A combinatorial signal that is computed directly or indirectly based on its own value is a part of a *combinatorial feedback loop*, sometimes shortened to just *feedback loop*. Combinatorial feedback loops can be stable (e.g. implement a constant driver or a transparent latch), or unstable (e.g. implement a ring oscillator). Amaranth prohibits using assignments to describe any kind of a combinatorial feedback loop, including transparent latches. -.. warning:: - - The current version of Amaranth does not detect combinatorial feedback loops, but processes the design under the assumption that there aren't any. If the design does in fact contain a combinatorial feedback loop, it will likely be **silently miscompiled**, though some cases will be detected during synthesis or place & route. - - This hazard will be eliminated in the future. - -.. TODO: fix this, either as a part of https://github.com/amaranth-lang/amaranth/issues/6 or on its own - .. note:: In the exceedingly rare case when a combinatorial feedback loop is desirable, it is possible to implement it by directly instantiating technology primitives (e.g. device-specific LUTs or latches). This is also the only way to introduce a combinatorial feedback loop with well-defined behavior in simulation and synthesis, regardless of the HDL being used.