From 145c685de03a0b5f70a3aa821ea1bd221c31d993 Mon Sep 17 00:00:00 2001 From: Clifford Wolf Date: Fri, 4 May 2018 21:59:31 +0200 Subject: [PATCH] Add ABC FAQ to "help abc" Signed-off-by: Clifford Wolf --- passes/techmap/abc.cc | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/passes/techmap/abc.cc b/passes/techmap/abc.cc index be86f642a..009ba6b97 100644 --- a/passes/techmap/abc.cc +++ b/passes/techmap/abc.cc @@ -1388,8 +1388,12 @@ struct AbcPass : public Pass { log("When neither -liberty nor -lut is used, the Yosys standard cell library is\n"); log("loaded into ABC before the ABC script is executed.\n"); log("\n"); - log("This pass does not operate on modules with unprocessed processes in it.\n"); - log("(I.e. the 'proc' pass should be used first to convert processes to netlists.)\n"); + log("Note that this is a logic optimization pass within Yosys that is calling ABC\n"); + log("internally. This is not going to \"run ABC on your design\". It will instead run\n"); + log("ABC on logic snippets extracted from your design. You will not get any useful\n"); + log("output when passing an ABC script that writes a file. Instead write your full\n"); + log("design as BLIF file with write_blif and the load that into ABC externally if\n"); + log("you want to use ABC to convert your design into another format.\n"); log("\n"); log("[1] http://www.eecs.berkeley.edu/~alanmi/abc/\n"); log("\n"); -- 2.30.2