IWR6843: Hardware Accelerator Complex Multiplication block output is always 0.

Atharva Jagdale

Part Number: IWR6843

I am trying to perform the multiplication in hardware accelerator. The snippet of configuration is attached here. Before configuring to complex multiplication mode, I have transfer data to Internal RAM by keeping it into FFT mode and disabling the complex multiplication block and FFT also (referred from another e2e thread). The data is getting stored there in Internal RAM that I have checked by putting breakpoints and looking into address. And there is data in memory-bank of HWA also (as required by this mode). But still the output is always 0. Is there anything more to be done here? Please guide if I am missing anything here.

over 2 years ago

0 Nathan Block over 2 years ago

TI__Mastermind 37805 points

Hi,

Please give us a day to answer this. Thank you for your patience.

Best,

Nate

0 Zorah Ahmad over 2 years ago

TI__Expert 4250 points

Hello,

Please go over the following threading to see if it helps resolve your issue

(14) AWR1843BOOST: AWR18xx HWA Complex Multiplication output is all zero - Sensors forum - Sensors - TI E2E support forums

0 Girish Veerendra Medisetty over 2 years ago

Prodigy 230 points

Hi Zorah,

To be clear,
We are using mmwave SDK3.5 with 6843-ODS board.
We are running whole RSP pipeline on DSP core(except Range proc).
after AOA (which is happening with DSP core FFT),we are doing this vector multiplication

What we did:
1. write one vector to internal RAM of HWA.

2. EDMA call to write another vector into HWA memory bank.

3. Call HWA paramset with complex multiplication.

Output:

Destination HWA memory bank has all zeros.

this link:https://e2e.ti.com/support/sensors-group/sensors/f/sensors-forum/957027/awr1843boost-awr18xx-hwa-complex-multiplication-output-is-all-zero
is not giving any information for us because those two scenarios mentioned by Gupta is not in our scope of implementation.

Please kindly help us. thanks in advance.

Regards,
Girish V M

0 Nathan Block over 2 years ago in reply to Girish Veerendra Medisetty

TI__Mastermind 37805 points

Hi Girish,

Can you compare your call the HWA to one of our examples in C:\ti\mmwave_sdk_03_06_00_00-LTS\packages\ti\drivers\hwa\test? This is a holiday week in the US, so we will not be able to address it until at least Monday. Thank you for your patience.

Best,

Nate

0 Girish Veerendra Medisetty over 2 years ago in reply to Nathan Block

Prodigy 230 points

There is no test code or example code for complex multiplication, yet we will try other ways.
Please let me know when your team is back with answer.
thanks in advance

0 Sudharshan KN over 2 years ago in reply to Girish Veerendra Medisetty

TI__Genius 10550 points

Hi Girish,

Please find additional details here

https://e2e.ti.com/support/tools/simulation-hardware-system-design-tools-group/sim-hw-system-design/f/simulation-hardware-system-design-tools-forum/1163535/complex-multiplication-in-hardware-accelerator?tisearch=e2e-sitesearch&keymatch=AWR%252520complex%252520multiplication#

https://e2e.ti.com/support/sensors-group/sensors/f/sensors-forum/1098518/awr2944evm-hwa-complex-multiplication-output-is-all-zero

Let me know if this helps!

Regards,

Sudharshan K N

0 Atharva Jagdale over 2 years ago in reply to Sudharshan KN

Prodigy 20 points

Hi Sudharshan,

We have followed the the same procedure explained there in first link. We were trying with small 16 bit integers for testing.

So because of factor 2^21 in denominator and small integers as inputs is it coming zero ?

Can you explain how the factor 2^21 come up.

And as you explained x[i]*y[i], is it element wise multiplication considering elements to be real or multiplication considering complex ?

And how will it work for only real data ?

Regards,

Atharva

0 Sudharshan KN over 2 years ago in reply to Atharva Jagdale

TI__Genius 10550 points

Hi,

Let me check and get back to you on the 1/2^21 factor.

Atharva Jagdale said:
And as you explained x[i]*y[i], is it element wise multiplication considering elements to be real or multiplication considering complex ?

These are complex numbers. for real data we should be able to use the same method. we will get back on the details.

Regards,

Sudharshan K N