Hi
> On Feb 21, 2017, at 9:50 PM, Trevor N. wrote:
>
> On Tue, 21 Feb 2017 07:37:34 -0500, BC wrote:
>>
>> Some 1588 chip sets have (or had, I havent looked recently) external sync
>> pins.
>> This does get into the whole, whats a motherboard / whats a peripheral
>>
q...@comcast.net said:
> I found while looking at the datasheets for newer Intel server ethernet
> cards that they have the ability to timestamp GPIO pin transitions, but none
> of them have their internal timebase synchronized to a counter in the CPU.
> It looks like they are clocked from a
On Tue, 21 Feb 2017 07:37:34 -0500, BC wrote:
>
>Some 1588 chip sets have (or had, I havent looked recently) external sync
>pins.
>This does get into the whole, whats a motherboard / whats a peripheral
>debate. Plugging in a 1588 card to get that pin probably no longer counts
>as a simple
Hi
> On Feb 20, 2017, at 9:26 PM, Trevor N. wrote:
>
> SA6CID wrote:
>>
>> So, I thought actually of the jitter added on the way between our
>> accurate source (GPS rx), until we can capture our timer. How much can
>> this be? As far as I see we don't have a capture mode
SA6CID wrote:
>
>So, I thought actually of the jitter added on the way between our
>accurate source (GPS rx), until we can capture our timer. How much can
>this be? As far as I see we don't have a capture mode for the HPET. But,
>if we have to do it in software, we get more than 100 ns jitter.
Time transfer over USB can be improved by timestamping on both ends, then
using a robust estimator for the clock offset. For example, imagine the
USB is a small microprocessor peripheral. It has a local timer, freely
incrementing, based on its local clock. When it gets a USB interrupt from
the
From: Chris Albertson
[]
What you care about is the uncertainty of this process NOT the offset but
the standard deviation of the offset.
.. and in the absence of numerical values of the SD, well-scaled graphs of
offset can show the variation in offset quite well.