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=-1.9 required=5.0 tests=BAYES_00 autolearn=unavailable autolearn_force=no version=3.4.4 X-Received: by 10.224.54.73 with SMTP id p9mr4807834qag.1.1373329174635; Mon, 08 Jul 2013 17:19:34 -0700 (PDT) X-Received: by 10.50.73.69 with SMTP id j5mr2517338igv.14.1373329174557; Mon, 08 Jul 2013 17:19:34 -0700 (PDT) Path: border1.nntp.dca3.giganews.com!border3.nntp.dca.giganews.com!border1.nntp.dca.giganews.com!nntp.giganews.com!t19no839745qam.0!news-out.google.com!f7ni1652qai.0!nntp.google.com!t19no839737qam.0!postnews.google.com!glegroupsg2000goo.googlegroups.com!not-for-mail Newsgroups: comp.lang.ada Date: Mon, 8 Jul 2013 17:19:34 -0700 (PDT) In-Reply-To: <1ca073mj5nq7$.8644vkeirvf4$.dlg@40tude.net> Complaints-To: groups-abuse@google.com Injection-Info: glegroupsg2000goo.googlegroups.com; posting-host=108.90.156.221; posting-account=qZVz2QoAAAAN9WxYp-9jYb7jORc4Zqwt NNTP-Posting-Host: 108.90.156.221 References: <8a3093bb-90b3-4081-9b0b-dfde5aa6b851@googlegroups.com> <993despcuk1d.1ifczvyo501px.dlg@40tude.net> <1ca073mj5nq7$.8644vkeirvf4$.dlg@40tude.net> User-Agent: G2/1.0 MIME-Version: 1.0 Message-ID: <6f36b546-7087-4ddc-b118-28e83a226c6a@googlegroups.com> Subject: Re: Point a beginner in the right direction? Cheap bare-board to run with a RTOS for running ADA From: mjsilva@scriptoriumdesigns.com Injection-Date: Tue, 09 Jul 2013 00:19:34 +0000 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable X-Original-Bytes: 2492 Xref: number.nntp.dca.giganews.com comp.lang.ada:182349 Date: 2013-07-08T17:19:34-07:00 List-Id: On Monday, July 8, 2013 1:45:21 PM UTC-7, Dmitry A. Kazakov wrote: > Consider frequency measuring. When a digital input toggles you have to >=20 > latch the real-time clock. Usually it is done from the interrupt routine. >=20 > The latency determines the error in the time/frequency measurement. Actually, with any of the smallish micros that we're talking about, the cap= ture of the timer value can be made to happen automatically upon the input = change. At the same time an interrupt can be generated to save off or othe= rwise deal with the just-captured value. > Polling becomes problematic when there are many inputs to handle or when >=20 > signals may get lost. The later is the case when you have to react on the >=20 > edge rather than on the level as in the example above. Interrupts are critical for most systems built around the smallish micros m= any of us are talking about.