[Discuss OpenCPI] AD9361 LVDS Interface Delays

From: Davis Hoover <dhoover_at_geontech.com>
Date: Fri, 27 Mar 20 13:46:37 -0400

Brian - please take a look at https://gitlab.com/opencpi/opencpi/-/wikis/AD9361-Integration-Guide and then let us know any remaining questions. This will give us an opportunity to improve that wiki page. Thanks!

Begin forwarded message:

> From: Brian Padalino <bpadalino_at_gmail.com>
> Date: March 27, 2020 at 11:54:02 AM EDT
> To: discuss_at_lists.opencpi.org
> Subject: [Discuss OpenCPI] AD9361 LVDS Interface Delays
>
> In the ad9361_data_sub HDL worker, there are the following LVDS interface
> delays listed:
>
> - DATA_CLK_Delay
> - RX_Data_Delay
> - FB_CLK_Delay
> - TX_Data_Delay
>
> Under the build XML file, it seems that these values need to be built for
> every variant that could possibly come up. This seems problematic since
> the values may be suboptimal for different sampling frequencies.
>
> I also see in the ad9361_config_proxy-spec.xml file, that for the
> ad9361_init struct, the same delays live there.
>
> When I've worked with these devices under linux in the past, ADI had a
> dynamic way they found/configured these values:
>
>
> https://wiki.analog.com/resources/eval/user-guides/ad-fmcomms2-ebz/interface_timing_validation
>
> So, now to my questions:
>
> - Is there a program somewhere, using OpenCPI, that performs the same
> dynamic eye checking to find optimal delays for the AD9361?
> - Is there a reason that the ad9361_data_sub is built multiple times with
> different default delays when it can be set dynamically for each radio?
>
> Thanks,
> Brian
>


Received on Fri Mar 27 2020 - 17:46:37 CDT

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