ADAU 1452 FIR length Sigma Studio

Hi all,

Am I right assuming that, if I want to implement a FIR filter in Sigma Studio for a ADAU1452 of 2400 taps, I have to set the length in SigmaStudio to 2401? I've read somewhere that the last coefficient of the filter is used as a bypass function. If the last coefficient is 1.0 then the FIR is bypassed, if 0.0 the filter is active.

For debugging purposses I implemented a 10 tap FIR filter and saw that the last coefficient toggles between 1.0 and 0.0 when I toggle the bypass control on the component in SigmaStudio :-)


I feel a bit stupid, now that I found that the last coefficient sent, is actually the first. I now think the "bypass" button on the FIR component does nothing more than creating a kind of unity fir filter when bypassed is chosen and uses the coefficients from the table when the FIR is not bypassed. Is that assumption correct?

Note: I installed SigmaStudio 4.5, but the help is empty...

With kind regards,


Added [update] section
[edited by: Reini at 12:44 PM (GMT 0) on 29 Nov 2019]