In message <20120315234624.a2da94430a247d235ca68...@kinali.ch>, Attila Kinali w rites:
>How good would that DAC need to be? Depends on the level of ambition ? >> 1-4MB RAM > >over a 256kB RAM it's get pretty thin if you want to stay in the uC >busines. Unless you want to use an ARM9 or better with external SDRAM >and Flash. But those are mostly BGA (very few QFP chips out there) and >they are assumed to run Linux or Windows CE on them... Support for bare >metal stuff is pretty thin. There is no problem running bare-metal on ARM9's, I've done it. But heck, it would be even better if you could load an OS on it, and still get your bits through. >On the other hand, if you dont have to support an OS and work on the >bare metal, you can get away with very little RAM. 128k is a damn lot >if you have to fill it with usefull data structures ;-) Well, if you want to do full-FRI averaging for a loran-chain, you need something like 99600*2 * 4 = 800Kb. If you want to do the full-hour averaging the WWVB doc talks about or DCF77 full-second phase-code, you need 2 MB for just the buffer. >> USB2 interface > >Which would mean you need a pretty recent chip as HighSpeed USB has not >been introduced into the uC world for more than 2 years or so. USB2, not USB3. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.