From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-0.3 required=5.0 tests=BAYES_00, REPLYTO_WITHOUT_TO_CC autolearn=no autolearn_force=no version=3.4.4 Path: border1.nntp.dca3.giganews.com!border3.nntp.dca.giganews.com!border1.nntp.dca.giganews.com!nntp.giganews.com!goblin2!goblin.stu.neva.ru!aioe.org!.POSTED!not-for-mail From: "Dmitry A. Kazakov" Newsgroups: comp.lang.ada Subject: Re: Point a beginner in the right direction? Cheap bare-board to run with a RTOS for running ADA Date: Mon, 8 Jul 2013 22:45:21 +0200 Organization: cbb software GmbH Message-ID: <1ca073mj5nq7$.8644vkeirvf4$.dlg@40tude.net> References: <8a3093bb-90b3-4081-9b0b-dfde5aa6b851@googlegroups.com> <993despcuk1d.1ifczvyo501px.dlg@40tude.net> Reply-To: mailbox@dmitry-kazakov.de NNTP-Posting-Host: xkOZ88C3T5fLavXpgyt3vA.user.speranza.aioe.org Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Complaints-To: abuse@aioe.org User-Agent: 40tude_Dialog/2.0.15.1 X-Notice: Filtered by postfilter v. 0.8.2 X-Original-Bytes: 1940 Xref: number.nntp.dca.giganews.com comp.lang.ada:182343 Date: 2013-07-08T22:45:21+02:00 List-Id: On Mon, 8 Jul 2013 15:31:32 -0500, Randy Brukardt wrote: > On a single-board computer, you don't really need interrupts because polling > works just as well (and you have nothing else that the machine might be > doing, preventing latency problems). Consider frequency measuring. When a digital input toggles you have to latch the real-time clock. Usually it is done from the interrupt routine. The latency determines the error in the time/frequency measurement. Polling becomes problematic when there are many inputs to handle or when signals may get lost. The later is the case when you have to react on the edge rather than on the level as in the example above. Interrupts are indeed rarely need if there is an OS. -- Regards, Dmitry A. Kazakov http://www.dmitry-kazakov.de