library/util_axis_fifo_asym: fix behavior when tkeep=0 #1914
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
LBFFilho
requested review from
AndreiGrozav,
PopPaul2021,
acostina,
gastmaier and
sarpadi
as code owners
|
I tested these changes with different tkeep masks on the SPI Engine and it works. I could not test different tkeep masks on the testbench here: https://github.com/analogdevicesinc/testbenches/tree/main/testbenches/ip/util_axis_fifo_asym |
|
Added a testbench for this (still a draft for now): analogdevicesinc/testbenches#246 |
Fix a bug where m_axis_valid waits on m_axis_ready to be asserted a few times in order to skip over data for which tkeep was all zeroes. This was a violation of the AXI Streaming protocol. Signed-off-by: Laez Barbosa <laez.barbosa@analog.com>
LBFFilho
force-pushed
the
asym_fifo_handshake
branch
from
e6b6df0 to
d99a25f
Compare
13 tasks
Fix tvalid low when tlast is present. Before this commit, util_axis_fifo would suppress all transfers with tkeep=0, even if tlast was asserted. This commit makes it so transfers with tlast asserted are preserved. The AXI-Streaming spec allows us to suppress transfers for which all tkeep bits are 0 (all bytes are null bytes), but only in the case when tlast=0 as well. Transfers where tlast is asserted can't be suppressed even when all bytes are null. Signed-off-by: Laez Barbosa <laez.barbosa@analog.com>
LBFFilho
force-pushed
the
asym_fifo_handshake
branch
from
d99a25f to
e49132e
Compare
caosjr
reviewed
Sep 24, 2025
Signed-off-by: Laez Barbosa <laez.barbosa@analog.com>
caosjr
approved these changes
Sep 25, 2025
|
Moved to draft due to recent discussions on the FIFOs affecting this PR. |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
AXI Streaming doesn't allow for tvalid to depend on tready (AMBA AXI-Stream Protocol Specification, 2.2 Handshake signaling).
The previous version of
util_axis_fifo_asymrelied on the downstream user asserting tready whenever there was data at the output that was invalid due to tkeep=0, even if tvalid was 0 in this case.In #1808 this forced us to introduce extra logic on the
spi_engineas a workaround. With this PR, we can skip that extra logic. If this is merged after #1808, we'll need to add a commit removing the workaround logic.This FIFO is used only in the
spi_engine(after #1808 ) anddata_offloadIPs. I tried to make the fix so it only affects theTKEEP_EN=1case, which would only affectspi_engine.PR Type
PR Checklist