Re: [Discuss-gnuradio] 1 PPS input for USRP2

[Matt Ettus]

subodh chiwate wrote:
> Hi,
> I just saw the specifications for USRP2. I wanted to know the use of 
> the 1 PPS and 10 MHz inputs.
> These are standard outputs of a GPS unit. So is it just a set of 
> external references or they are used in the ethernet time stamping?


The USRP2 has a 100 MHz clock internally.  That clock will be locked to 
the 10 MHz reference you provide.

Samples can be time stamped, and that time can be calibrated to the 1 
PPS signal.  In the most general case, that 1 PPS input just goes 
directly to the FPGA, so internally you can do whatever you want with it.

Matt