SigmaDSP Device Selection Question from Customer

Discussion created by BrettG on Aug 1, 2012
Latest reply on Aug 5, 2012 by tonyc

I just received this question from a customer:

I'm looking a recommendation for the 'best' eval board for a 40-band

2-channel (simple left/right) audio 'equalizer' type application. The

SigmaDSP will take left and right channel line level input signals and

process each identically.The signal processing functions include, but

aren't limited to: mixing (addition), filtering, modulation

(multiplication), sinusoidal generation, peak detection, channel-to-channel

'sychronization', etc... Yes, it's a complicated sound processing



I'm new to the product line and tool set, but from what I see it looks like

a great fit. Any other 'newbie' advice is appreciated...

Here is my response:


I think the SigmaDSPs best suited for this application would be either the ADAU1701, ADAU1761, or ADAU1446. You can find details about each of those on their respective product pages.


Each of those products has slightly different DSP core architectures, so there's a minor difference in the amount of processing cycles required to run a given algorithm on each of them. Based on your description, I would guess that the processing you require will *probably* fit in the memory of the ADAU1701 or ADAU1761... It will *definitely* fit in the memory of the ADAU1446.


The ADAU1446 can compute 3584 instructions per sample, whereas the ADAU1701 and ADAU1761 can only compute 1024 instructions per sample. The downside of using the ADAU1446 is that it doesn't have internal audio ADCs or DACs. You'll need to make the decision based on the amount of processing you need.


More info is available on the product selection table here:


You can use the resource tables on our Wiki to calculate approximately how many instructions will be required for your use case:

(Right now the resource summary exists only for ADAU144x, ADAU1761, and ADAU1781 SigmaDSPs. The resources used by other SigmaDSPs approximately matches these numbers, with minor differences.)


Another way to evaluate which processor fits the best would be to download SigmaStudio and build/compile the project to see if it fits the memory limitations of each device.