HDL FIFO Reset Problem

Hi,

I'm working with HDL FIFO Classic Module and I've discovered that when I do a reset (to local reset port) , FIFO Number of register entries turns to 1 and the empty signal turns to low level. Are there anything wrong with Classic HDL FIFO module or am I missing something?

NOTE: And HDL code generated does just the descrived above

fifo_sample_count_next <= to_unsigned(16#0001#, 16) WHEN rst /= '0' ELSE
fifo_sample_count + to_unsigned(16#0001#, 16) WHEN (fifo_write_enable AND ( NOT fifo_read_enable)) = '1' ELSE
fifo_sample_count + to_unsigned(16#FFFF#, 16) WHEN (( NOT fifo_write_enable) AND fifo_read_enable) = '1' ELSE
fifo_sample_count;

Answer 1

[Kiran Kintali]

Would you be able to share your sample model? You can prune it to just show HDL FIFO block.

Found a relevant report here. Need to investigate further if the issue is identical.

https://www.mathworks.com/support/bugreports/2982578

An update patch is planned for this bug.

[Juan Martin de las mulas]

I've attached a simulink model only with FIFO HDL reset, and the Logic Analyzer shows how the signal turns to 1 after the reset is received. Maybe is it related with the HDL optimization options? I think is something so basic that Im missing something...

Thanks!

[Kiran Kintali]

please share the mask variables or hardcode the sizes for this pruned model.

(DetectionSize/4)*MaxNumDetections

[Juan Martin de las mulas]

Sorry Kiran, it's 42000. But it doesn't matter the value I set there... always the same result.

Thanks!

[Kiran Kintali]

The issue is fixed in latest release; what is the version of MATLAB you are using? We would like to provide an update.

[Kiran Kintali]

The issue is resolved in the latest releases of MATLAB and HDL Coder and is being backported to previous releases. https://www.mathworks.com/support/bugreports/2982578

Do not hesitate to reach out to tech support for the update release information.

[Juan Martin de las mulas]

Hi Kiran. I'm using Matlab 2022 version. I wasn't asserting reset and pop at the same time, only set reset, but in any case... thanks!