Path: ...!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail From: Stefan Monnier Newsgroups: comp.arch Subject: Re: Scan chains Date: Wed, 07 May 2025 15:03:31 -0400 Organization: A noiseless patient Spider Lines: 12 Message-ID: References: <2025Apr23.194456@mips.complang.tuwien.ac.at> <126700f99b6f97d7483bb5355d68c361@www.novabbs.org> <0b410ad93124778a2b1b3ab8fb6ec62c@www.novabbs.org> <54dcb50f7a378240447d3565f083f0bc@www.novabbs.org> <5j3SP.1331$RXsc.334@fx36.iad> <1ebeaab74e7a847fa6f9fd39adccdd1b@www.novabbs.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Injection-Date: Wed, 07 May 2025 21:03:32 +0200 (CEST) Injection-Info: dont-email.me; posting-host="3f39107eab3c17e0c0071fc9fda2e4bc"; logging-data="1251277"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX18Sy0e0b5kUhUTRxUunzzq4IrOekAnR4qs=" User-Agent: Gnus/5.13 (Gnus v5.13) Cancel-Lock: sha1:oUtIzKTzkscoO4gcHRwpVE+1z6g= sha1:rf6raB0hVXN+eLr0v1Ap3ya8HTM= Bytes: 2068 >> What's the approximate cost of those scan chains. I.e. if we were to >> take an existing working design and replace all the "flip-flop with >> scan-chain" with "plain flip-flops", how much smaller would the >> resulting chip be, how much faster could it run, and how much less power >> could it consume? > Given a 16-gate delay design with 5 gates of "flop-jitter-skew" > the scan path adds about ½ a gate of delay (2%-ish). Almost lost in the noise. Thanks. Stefan