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Re: Time problem: Clock running slow
- From: Grant Edwards <grant dot b dot edwards at gmail dot com>
- To: ecos-discuss at sources dot redhat dot com
- Date: Thu, 2 Sep 2010 12:52:06 +0000 (UTC)
- Subject: [ECOS] Re: Time problem: Clock running slow
- References: <201009021031.18420.ilindner@logopak.de>
On 2010-09-02, Iris Lindner <ilindner@logopak.de> wrote:
> Hi everyone,
> we just encountered a problem with our clock: It is running slow with
> approximately 24 seconds per hour.
[...]
> The real-time clock constants are: numerator=1 000 000 000,
> denominator=1000, period=66500 (so 1 tick = 1 ms). (And I've verified
> the chip's I/O bus speed as well as the basic core speed.)
When you say "verified" do you mean with a recently calibrated
frequency counter? Your error is only 100ppm (0.01%).
> Could there be a problem with these constants? Or perhaps interrupts
> disturbing the clock interrupt? Thanks in advance for any help / idea
> / comment!! cu Iris
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