Getting error in HDL Optimized RS Encoder for ufix4 data type

I am working with an example program using HDL optimized RS encoder/decoder. You can find the example here

https://www.mathworks.com/help/comm/ug/using-hdl-optimized-rs-encoder-decoder-library-blocks.html

It is working fine for N = 255, K = 239 and HDL files are being generated perfectly.

Then I tried N = 15, K = 9 by adjusting the paramters and encoder/decoder polynomial [1 0 0 1 1] according to that, I get correct simulations result and HDL file is also generated.

But when i put N=11, K=9 for the same polynomial, the simulation works fine and it gives thecorrect result but while generating the HDL file, I get this error

In case you need to adjust the model according to my paramters, I am attaching screenshots by which you make the alterations.

[Bharath Venkataraman]

Can you try using fixdt(0,4,0) for the table data type?

Also, it would help if you are able to show a snapshot of the inputs and outputs of the RS block with datatypes shown.

[Hassaan Saeed]

Yeah I also tried fixdt (0,4,0), the results are same. I also checked the model for N = 13, K = 9, it is working with this configuration but not with N = 11. I'll attach the snapshot of input and output in a while

[Hassaan Saeed]

Please take a look into these snapshots. Thank you.

Answer 1

[Mounika Sheela]

Hi Hassaan,

This is a known issue for the Integer-Input RS Encoder HDL Optimized block from Comms Toolbox. The block doesn't support HDL code generation for RS Codes with parity length 2 (N=11 and K=9). This issue is fixed in RS Encoder block from WHDL Toolbox, you can use this one for your work.

[Hassaan Saeed]

Thanks for the reply. I tried RS Encoder block from WHDL Toolbox, generated the HDL code and then integrated with an IP node. It is working perfectly.

Then I tried the same for RD Decoder from WHDL Toolbox for N = 11 and K = 9. For No. of messages > 1, it is not returning any valid data at all. It works fine for No. of messages == 1.

You can find the example that I am using from here.

https://www.mathworks.com/help/wireless-hdl/ref/rsdecoder.html

P.S.

Working for (N = 255 and K = 239), (N = 31 and K = 27)

Not working for (N = 11 and K = 9), (N = 31 and K = 25) and for all combination of u4 data type as far as i checked.