Re: Ettus N210 clock test header

[Marcus Müller]

Hi Fabien,

I bet the usrp-users mailing list would be a better place to ask this!
Anyways, yep, you can. Call the usrp2_clock_ctrl.enable_test_clock() 
routine. From the top of my head, multi_usrp doesn't expose that 
directly, but you could easily do, roughly:

0. get the source code of **exactly** the UHD you're using (we don't 
want to end up having to recompile everything that uses it because we're 
using even a slightly different ABI).
Assuming that's the UHD that came with your linux distro, use `dnf 
download --source uhd` (for fedoroids), `apt-get source uhd` (for 
debian, and debianoids like ubuntu)…, and follow the build instructions 
on how to build local packages (`fedpkg local` on fedora, `debuild -b 
-uc -us` on debian)

1. find usrp2_impl::usrp2_impl in the source code
2. in the loop going over all motherboards, add something like:
   _mbc[mb].clock.enable(true);
3. build and install (the package, if applicable)

Cheers,
Marcus

PS: instead of hardcoding the clock to be enabled, you can also add a 
property tree entry like this instead (from the top of my head, didn't 
even try to type that into anything with syntax checking):

   tree->create<bool>(mb_path / "test_clock" / "enable")
       .set_coercer(
           boost::bind(
               &usrp2_clock_ctrl::enable_test_clock,
               _mbc[mb].clock,
               _1
       ))
       .set(true);

That way, you get a property tree entry that you can set / unset at runtime.


On 27/06/2022 13.03, Fabien PELLET wrote:
> Hello,
>
> How can I enable the test clock output on J503 in my USRP N210 ? Is 
> there a way to do that only using UHD methods that I can use in my C++ 
> code ?
>
> I would like to use it on a hardware I'm designing that need to be 
> perfectly synchronised with the internal DAC, ADC and FPGA.
>
> Thanks for the help,
>
> Best regards,
>
> Fabien, F4CTZ.

smime.p7s
Description: S/MIME Cryptographic Signature