From 4c0404ae024e9595934e738a3e8f52be9c22d090 Mon Sep 17 00:00:00 2001 From: Eddie Hung Date: Fri, 23 Aug 2019 10:24:59 -0700 Subject: [PATCH] Mention clkbuf_inhibit can be overridden --- README.md | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/README.md b/README.md index 00b631237..38ca77862 100644 --- a/README.md +++ b/README.md @@ -332,17 +332,18 @@ Verilog Attributes and non-standard features that represent module parameters or localparams (when the HDL front-end is run in -pwires mode). -- The ``clkbuf_inhibit`` attribute can be set on a wire to prevent - automatic clock buffer insertion by ``clkbufmap``. - -- The ``clkbuf_sink`` attribute can be set on an input port of a blackbox - module to request clock buffer insertion by the ``clkbufmap`` pass. - - The ``clkbuf_driver`` attribute can be set on an output port of a blackbox module to mark it as a clock buffer output, and thus prevent ``clkbufmap`` from inserting another clock buffer on a net driven by such output. -- The ``iopad_external_pin`` attribute on a blacbox module's port marks +- The ``clkbuf_sink`` attribute can be set on an input port of a module to + request clock buffer insertion by the ``clkbufmap`` pass. + +- The ``clkbuf_inhibit`` is the default attribute to set on a wire to prevent + automatic clock buffer insertion by ``clkbufmap``. This behaviour can be + overridden by providing a custom selection to ``clkbufmap``. + +- The ``iopad_external_pin`` attribute on a blackbox module's port marks it as the external-facing pin of an I/O pad, and prevents ``iopadmap`` from inserting another pad cell on it. -- 2.30.2