[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

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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