Date: Mon, 12 Feb 96 21:17 WET From: uhclem@nemesis.lonestar.org (Frank Durda IV) To: hackers@freebsd.org Subject: Re: Watchdog timer - update Message-ID: <m0tmBEz-000CCbC@nemesis.lonestar.org>
next in thread | raw e-mail | index | archive | help
A week or two ago when we were talking about the watchdog timer, someone asked when a design had to be certified for Part 15 compliance. I could not recall the precise answer at the time, but I've done a little checking and thought I would give you the results. 1. If the device generates or uses frequencies of 9KHz (nine kilohertz) or more, it must be certified. This is covered in Title 47 USC, Part 15 for the US, and EN 55022 and 50082 for the EU. 2. If the device consumes less than 7 nanowatts of overall power, it does not need certification (US) regardless of the frequencies generated or used. This exception is apparently there for digital wristwatches, which do not require certification. So there it is. Any microprocessor with even feeble computing power trying to interface to an ISA or PCI connector will probably exceed the power requirements and force certification. Now it is possible to clock several different CMOS-style processors at a speed below 9KHz (CMOS devices usually have static clocking states), but the CPU would not be able to do very much. Supposedly the FCC regulations are on the FCC web site, so you can examine them there for any other details. Frank Durda IV <uhclem@nemesis.lonestar.org>|"The Knights who say "LETNi" or uhclem%nemesis@rwsystr.nkn.net | demand... A SEGMENT REGISTER!!!" ^------(this is the fastest route)|"A what?" or ...letni!rwsys!nemesis!uhclem |"LETNi! LETNi! LETNi!" - 1983
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?m0tmBEz-000CCbC>