From 9535c0b56dd02772b65de5c8f29a43257f3e12c0 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Matthias=20K=C3=B6fferlein?= Date: Sun, 3 Feb 2019 22:29:30 +0100 Subject: [PATCH] Created 2019 02 03 (markdown) --- 2019-02-03.md | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) create mode 100644 2019-02-03.md diff --git a/2019-02-03.md b/2019-02-03.md new file mode 100644 index 0000000..3ae5ebc --- /dev/null +++ b/2019-02-03.md @@ -0,0 +1,25 @@ +# Implicit connection of nets with same label + +Nets labelled with the same text are now implicitly connected even if there is no physical connection. +This can be useful to verify subcircuits. For example, a layout cell may use two different power nets which need to be connected on a higher hierarchy level. Without implicit connections it's not possible to verify the layout cell's functionality, because the connectivity extraction will render two power pins. + +The implicit connection feature allows putting the same label on those two nets and make the nets +connected this way. It's not important which layers the nets are on. Only labels on the same hierarchy +level are considered. + +Top-level layouts must not be extracted with this feature. Otherwise, opens may not be detected if both parts of +the nets are labelled with the same label. Hence, this feature is configurable. + +The respective switch is the new "join_nets_by_label" argument of ```LayoutToNetlist#extract_netlist```. + +By default, implicit connections are enabled. To disable implicit joining of nets, use + +``` +l2n = RBA::LayoutToNetlist::new +... +# extract netlists with implicit joining disabled +l2n.extract_netlist(false) +``` + + +