A digital DC bias caused by various truncations in the DDC chain was
previously noticable with small signal levels, especially with high
decimation rates. This patch eliminates the bias by replacing the
truncation with rounding or simply keeping more bits for longer where it
makes sense.
This is essentially a forward port of a similar prior fix to the usrp2
DDC chain: https://github.com/EttusResearch/fpga/pull/4.
Signed-off-by: Ryan Volz <ryan.volz@gmail.com>
Original-commit: a57c162a0d11ab82a83c911a94272ceb6f7ff70a
The asynchronous feedback loop on the err signal causes X to get stuck
on the sum signal when simulating. This change adds a check for
simulation only to force X to 0 so that unknown inputs get resolved
once the inputs are known.
Also added default values to the ports out and strobe_out, since having
them uninitialized and without reset was causing simulation issues in
other modules. The FPGA will initialize them to 0, so this change makes
the code equivalent to real hardware behavior.
Original-commit: b9f7af5807f73a5ac2612ea42ac2b65c26a3bff2
The FPGA codebase was removed from the UHD repository in 2014 to reduce
the size of the repository. However, over the last half-decade, the
split between the repositories has proven more burdensome than it has
been helpful. By merging the FPGA code back, it will be possible to
create atomic commits that touch both FPGA and UHD codebases. Continuous
integration testing is also simplified by merging the repositories,
because it was previously difficult to automatically derive the correct
UHD branch when testing a feature branch on the FPGA repository.
This commit also updates the license files and paths therein.
We are therefore merging the repositories again. Future development for
FPGA code will happen in the same repository as the UHD host code and
MPM code.
== Original Codebase and Rebasing ==
The original FPGA repository will be hosted for the foreseeable future
at its original local location: https://github.com/EttusResearch/fpga/
It can be used for bisecting, reference, and a more detailed history.
The final commit from said repository to be merged here is
05003794e2da61cabf64dd278c45685a7abad7ec. This commit is tagged as
v4.0.0.0-pre-uhd-merge.
If you have changes in the FPGA repository that you want to rebase onto
the UHD repository, simply run the following commands:
- Create a directory to store patches (this should be an empty
directory):
mkdir ~/patches
- Now make sure that your FPGA codebase is based on the same state as
the code that was merged:
cd src/fpga # Or wherever your FPGA code is stored
git rebase v4.0.0.0-pre-uhd-merge
Note: The rebase command may look slightly different depending on what
exactly you're trying to rebase.
- Create a patch set for your changes versus v4.0.0.0-pre-uhd-merge:
git format-patch v4.0.0.0-pre-uhd-merge -o ~/patches
Note: Make sure that only patches are stored in your output directory.
It should otherwise be empty. Make sure that you picked the correct
range of commits, and only commits you wanted to rebase were exported
as patch files.
- Go to the UHD repository and apply the patches:
cd src/uhd # Or wherever your UHD repository is stored
git am --directory fpga ~/patches/*
rm -rf ~/patches # This is for cleanup
== Contributors ==
The following people have contributed mainly to these files (this list
is not complete):
Co-authored-by: Alex Williams <alex.williams@ni.com>
Co-authored-by: Andrej Rode <andrej.rode@ettus.com>
Co-authored-by: Ashish Chaudhari <ashish@ettus.com>
Co-authored-by: Ben Hilburn <ben.hilburn@ettus.com>
Co-authored-by: Ciro Nishiguchi <ciro.nishiguchi@ni.com>
Co-authored-by: Daniel Jepson <daniel.jepson@ni.com>
Co-authored-by: Derek Kozel <derek.kozel@ettus.com>
Co-authored-by: EJ Kreinar <ej@he360.com>
Co-authored-by: Humberto Jimenez <humberto.jimenez@ni.com>
Co-authored-by: Ian Buckley <ian.buckley@gmail.com>
Co-authored-by: Jörg Hofrichter <joerg.hofrichter@ni.com>
Co-authored-by: Jon Kiser <jon.kiser@ni.com>
Co-authored-by: Josh Blum <josh@joshknows.com>
Co-authored-by: Jonathon Pendlum <jonathan.pendlum@ettus.com>
Co-authored-by: Martin Braun <martin.braun@ettus.com>
Co-authored-by: Matt Ettus <matt@ettus.com>
Co-authored-by: Michael West <michael.west@ettus.com>
Co-authored-by: Moritz Fischer <moritz.fischer@ettus.com>
Co-authored-by: Nick Foster <nick@ettus.com>
Co-authored-by: Nicolas Cuervo <nicolas.cuervo@ettus.com>
Co-authored-by: Paul Butler <paul.butler@ni.com>
Co-authored-by: Paul David <paul.david@ettus.com>
Co-authored-by: Ryan Marlow <ryan.marlow@ettus.com>
Co-authored-by: Sugandha Gupta <sugandha.gupta@ettus.com>
Co-authored-by: Sylvain Munaut <tnt@246tNt.com>
Co-authored-by: Trung Tran <trung.tran@ettus.com>
Co-authored-by: Vidush Vishwanath <vidush.vishwanath@ettus.com>
Co-authored-by: Wade Fife <wade.fife@ettus.com>
Original-commit: bafa9d95453387814ef25e6b6256ba8db2df612f
Max Köhler