( ESNUG 393 Item 1 ) --------------------------------------------- [04/25/02]

From: Jerry Yang <yangj@nortelnetworks.com>
Subject: Do You Prefer Synchronous or Asynchronous Resets In Your Designs?

Hi John,

We are starting a new ASIC design and had new member coming from another
group.  When discussing methodology, our new collegue suggested using a
synchronous reset flip-flop over asynchrous flip-flop which was a shock
to us.  Our past design guideline has been using async reset flops only
(because all ASIC vendors we know about only have async reset flops in
their libraries, so if you choose to code a sync reset flop the
Synthesis tool will try to build some logic in front of your D pin). 

Do your readers have any suggestions on this?

    - Jerry Yang
      Nortel Networks                            Nepean, Ontario, Canada