AnsweredAssumed Answered

Sigmastudio not saving IIR table coefficients in index selectable filter

Question asked by Gertjan on Nov 22, 2013
Latest reply on Jan 22, 2014 by Gertjan

Dear Analog Devices,


I have been using Sigmastudio in combination with the ADAU1445 for a while now for a high-end audio application. For a next set of features I am using an index selectable filter with around 12 IIR coefficient filters where the coefficients are entered in the IIR table window. Everything works sweet while entering the coefficients and plotting them. However, when saving the design and opening it again, all A1 coefficients are zero. When entering the A1 coefficient again manually it is back to original. Until I remove filters that is, it seems that filter all filter responses change! This looks like a problem to me with storing and retrieving the coefficients? Also I also noticed when entering the coefficients using the TAB button, switching to the A1 field takes one TAB press more; this might hint to another implementation problem as well?


This currently is a real show-stopper for us; uploading the coefficients from our microcontroller is not an option as a smooth (through the slew function) transition from one filter to another is needed.


Thanks a lot in advance and regards,