[HLS 2019.1] Using blackbox example (Jason file)

[gsutter]

I would like to start using the blackbox feature in HLS. I searching for extra documentation and/or an example but I´m not able to found nothing.
I saw only one post asking some question, but nothing else.
Any suggestion to start with?

Thank you in advance, Gustavo

[ebrahimm]

Hi Gustavo,

Here is an RTL Blackbox JSON File Example from the Vivado High Level Synthesis User Guide. 

https://www.xilinx.com/support/documentation/sw_manuals/xilinx2019_1/ug902-vivado-high-level-synthesis.pdf#page=587

Scroll through the userguide to see other beneficial information, like more RTL Blackbox information:

https://www.xilinx.com/support/documentation/sw_manuals/xilinx2019_1/ug902-vivado-high-level-synthesis.pdf#page=295

Hope that helps!

Ebrahim

[shameera]

Hi @gsutter ,

Please check the below link of Github which has an example of using RTL as black box.

https://gitenterprise.xilinx.com/frederic/HLS-Tiny-Tutorials/tree/master/misc_rtl_as_blackbox

[gsutter]

Hi Ebrahim and Shameera,

Thank you for the answers. I already review the UG902. Until now is the only source of information that I found.

The proposed link at Github seems to be not a public address (gitenterprise.xilinx.com) or is temporally unavailable. Any idea?

Best Regards, GS

[shameera]

Hi @gsutter ,

Please check the archived project attached here for RTL as black box example. This has been imported with Vivado 2019.2 release.

[gsutter]

Hi Shameera,

Thank you very much! I will install 2019.2 and test it ASAP.

Best Regards, GS

[gsutter]

Hi Shameera,

You miss the verilog file (rtl_model.v) that is used in the jason file.

Best Regards, GS

[shameera · Accepted solution]

Hi @gsutter ,

If you have installed Vivado 2019.2, then you should be able to open the RTL as Blackbox example from the examples that were exported with Vivado 2019.2.

Anyhow, I have also attached the RTL file for your reference.

[gsutter]

Hi,

Thank you I have found the example in the installation, just before to check your answer.

Thank you very much for your help and information.

Best Regards, GS

[mati@logtel.com]

Hello,

Looking into the provided info I still can't find a way to use the ap_return in my rtl.

the example provided is not using ap_return and the only info is in the JSON file example (lised above).  That info is not enough - all options I tried ended with an error during HLS synthesis.

Can someone share an example how to use a return value (ap_return) in the rtl module as blackbox?

Thanks,

Mati