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Date:      Wed, 08 May 2024 05:35:15 +0000
From:      "Poul-Henning Kamp" <phk@phk.freebsd.dk>
To:        John Hay <john@sanren.ac.za>
Cc:        freebsd-hackers@freebsd.org
Subject:   Re: FreeBSD driver for the OCP TAP Time Card
Message-ID:  <202405080535.4485ZFN9066673@critter.freebsd.dk>
In-Reply-To: <CAGv8uar=CmAXowLUS1H2hEHk3OPJPifgXSy3Ru9VodRcoy4yPA@mail.gmail.com>
References:  <CAGv8uar=CmAXowLUS1H2hEHk3OPJPifgXSy3Ru9VodRcoy4yPA@mail.gmail.com>

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--------
John Hay writes:

> I have been working on a FreeBSD driver for the Open Compute Project (OCP)
> Time Appliance Project (TAP) Time Card. The card consists of three main
> parts, a clock module, a GNSS module and a FPGA module. The firmware for
> the FPGA implements a counter that is synchronized to TAI using the GNSS
> module and the clock module. The counter is implemented as two 32-bit
> registers, seconds and nanoseconds, like struct timespec, and make that
> available on the pci-e bus.

That is /precisely/ the kind of hardware timecounters were designed for :-)

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk@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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