[time-nuts] Thought experiment on a low cost timing board
Poul-Henning Kamp
phk at phk.freebsd.dk
Mon Feb 27 06:51:58 EST 2006
In message <440238BA.7030403 at chello.nl>, Paul Boven writes:
>How about taking one of the bigger FPGA's, that can hold a complete
>stand-alone microcontoller, running a Unix-like OS? You could implement
>several fast, wide synchronous counter/latches in the same FPGA fabric,
>so there would be no need to bother with things like PCI busses. Does
>FreeBSD run on any of these chips?
>
>With a serial (for NMEA) and PPS input, and ethernet output, you'd have
>an NTP-server-on-a-chip. Add a D/A-converter to discipline a TCXO, and
>you're all set. An FPGA with relatively few pins, hence no BGA, would
>suffice. Building such a device would be within the capabilities of some
>of the more dedicated timenuts in here.
You can do most, if not all of this with a single-chip microcontroller
already.
The simpler your computer, the simpler timekeeping is.
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk at 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.
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