Re: [Discuss-gnuradio] Reg:Tags_demo.cc example

[Sean Nowlan]

On 03/12/2013 02:14 PM, Josh Blum wrote:
> On 03/11/2013 09:52 PM, john jade wrote:
> > Hi,
> >
> > 1. What is get_full_seconds and get_frac_seconds printing?
> Its probably the receive timestamp, its the time stamp from this object:
>
> http://files.ettus.com/uhd_docs/doxygen/html/classuhd_1_1time__spec__t.html
>
> > 2.Can we get upto precision of nano seconds using the above methods and
> > please tell me how to do it.
> The fractional seconds are stored as double precision floating point.
> This gives the fractional seconds enough precision to unambiguously
> specify a clock-tick/sample-count up to rates of several petahertz.
Although time can be *represented* with petahertz+ resolution, doesn't 
the hardware clock constrain the *realizable* resolution? For example on 
a USRP with a 100 MHz FPGA clock, would actual transmit precision be 
limited to 10 ns?

> -josh
>
> > In the frac seconds i am getting 0.xxxxxx(only 6 digits after point-micro
> > seconds)
> >
> > Thanks
> >
> >
> >
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