Connecting a commercially available DSP to SigmaStudio?

Started by InnovationAudio 3 years ago10 replieslatest reply 3 years ago640 views

I'd like to add an upmixer software module to an existing commercially available DSP (Car Audio) with a Sharc chip. 

I see the Jtag header on the circuit board (unpopulated). 

But, From what I understand (I don't know much). I will need to connect the DSP to a USB-I emulator. 

I do have a Sharc development board. Would I be best to remove the DSP chip from the DSP and install it onto the development board to connect it to SigmaStudio?

If anyone is able to guide me through this process. I'd be very grateful. 


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Reply by drmikeSeptember 1, 2021

I would go the other way myself.  Connect the jtag pins from the development board to the DSP board and disconnect power to the eval board chip.  The main problem will be does the software work with that DSP connected on the jtag lines.

The advantage of this is your dsp is in it's natural environment and the software will respond to the actual hardware of the system.  Once it works, you just disconnect the jtag lines and you're done.  

In principle it should work, but the eval software may not like having a different dsp chip out there.

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Reply by InnovationAudioSeptember 1, 2021

So. I can connect the USB-I interface to the Eval board. Solder a Jtag header into the car audio DSP. Connect the two. Remove the USB power from the USB-I interface to the development board. Power up the car audio DSP. And I should be able to connect to the car audio DSP? 

The eval software is from an Aliexpress eval board. Appears to be cracked. So, I'm hoping it will ignore any sort of protection that will look for a serial number or something like that. 

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Reply by drmikeSeptember 1, 2021

Yep.  Make sure the jtag lines are as short as possible, good grounding all around, and hardware wise it should work.  Software is a whole 'nother ball of wax.

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Reply by InnovationAudioSeptember 1, 2021

The development board has a separate board for the DSP chip/Jtag/USBi. So. If I just remove that board. It will be completely separated from the power supply.

The DSP I'd like to modify is a 12vdc unit. 

I would be connecting the USBi to my laptop. So it would be completely isolated from ground. Is that an issue? 

Would I use crosscore or Sigmastudio for Sharc to communicate with the DSP? 

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Reply by BEBSynthesizersSeptember 1, 2021

I don't really understand what you call a "commercially available DSP". SigmaDSP are commercially available since 15 years and SigmaStudio was created specifically for them.

Maybe I am wrong, but your question looks like "I have a Motorola DSP but I want to program it with Analog Devices tools", which is quite a weird approach

Second problem : SigmaStudio knows nothing about JTAG probes. SigmaStudio generates source code, assembles it and sends it to SigmaDSP using SPI or I²C lines (as SigmaDSP do not have any JTAG interface)

Or are you talking of the "SigmaStudio for SHARC" ? Which is a completely product. SigmaStudio for SHARC is nothing else than a code generator. It does not compile or assemble anything, and even less debug anything.

Note that SigmaStudio for SHARC is terribly reduced version of SigmaStudio. Many DSP blocks existing in SigmaStudio for SigmaDSP do not exist in the SHARC version (because ADI wants to keep the source code secret). With SigmaStudio for SHARC, you will only have access to a very limited subset of blocks.

And as SigmaStudio for SHARC does not compile or assemble anything, you will need the SHARC Toolchain (previously called "Visual DSP++") which is pretty expensive (except if you buy a development board from ADI, you will get the toolchain for free, but with some codesize limitations)

And last thing : JTAG probe made by ADI is *awfully* expensive. There are some chinese clones which are 10x cheaper, but don't expect any support from ADI if you use them


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Reply by InnovationAudioSeptember 1, 2021

I'm not sure why you would think I'm trying to connect a different brand of DSP chip to Sigmastudio?

"I'd like to add an upmixer software module to an existing commercially available DSP (Car Audio) with a Sharc chip." This is a working product you can buy to connect to your car audio system with a Sharc chip inside. 

I'm using a commercially available completed car audio DSP with a Sharc chip. I have a Sharc development board with the same chip (ADSP-21489). 

I want to add a Dolby Prologic IIz software module to this chip to add surround sound. 

I would like to know the proper way to do this. 

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Reply by chalilSeptember 1, 2021

hope you're trying to use SigmaStudio for SHARC to program ADSP-21489 Ezkit. 

If that is the case, in addition to the EzKit, you need to have USBi connector, SigmaStudio™ USBi to EZ-Board Adapter. check digikey, for example. 

once you have the above 3, you need to have the following :

1. crosscore embedded studio ide 

2. SigmaStudio tool 

3. SigmaStudio for SHARC FW. 

with the above you create and run post processing schematic on your kit. 

to integrate DPLII you need to get the sharc library and add to the sharc FW.

hope it helps. 

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Reply by InnovationAudioSeptember 1, 2021

Good news. I do have the USBi. Crosscore and Sigmastudio.

I have successfully connected the DSP to Sigmastudio. I used the EZkit to find which pins to connect the USBi to. 

I've already had a phone interview with Dolby and I'm just waiting for them to find the correct agreement for me to sign to get the licence.

This is a commercially available car audio DSP (A finished product)that I'm trying to modify. 

Upon connecting Sigmastudio. It would appear I've deleted the firmware currently on the chip. 

So, I'm just trying to figure out how to proceed. I tried to reload the factory firmware. But, I'm guessing that only loads onto the MCU. 

This board has 2 multichannel DACs. So, I assume I'll need to figure out which one is connected to which pin and get the DAC and ADC specs and rebuild that as well as figure out how to get it to boot. 

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Reply by chalilSeptember 1, 2021


one of the easiest way to verify that the interconnections are correct is to create a tone generator schematic to play that through the speakers.  when you compile and download from sigmastudio you should hear audio in the respective speakers.