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Schematic is not working properly after modifying the Frame Sync Detection settings

Question asked by bochoi on Aug 6, 2018

Hi ADI Team,,  



     I am using the following version Sigma Studio and SS4SH in 21489 


SigmaStudio - 3.14

SS4SH - Rel2.2.0 


   Based on the demo application , I modified the application and adapt into our target HW which is running TDM512 ( 16 Channel ) audio format.   

   Firstly , it is working fine with Sigma Studio .  I can create a new schematic with 16 Input and 16 output and it is bale to tune the parameters of each software module.  Also it is possible to boot up from external flash with ldr including schematic + parameters. 

   Unfortunately,  it is required to change the frame sync width from 1 BCLK to 32 BCLK in order to meet the specification of  our chosen ADC & DAC.    So we made the below changes for TDM TX and RX 


/* SPORT 1 for RX , frame sync detection - falling edge */ 

*pSPCTL1 = (SLEN32 | SCHEN_A | SDEN_A | LMFS );   <---- add |LMFS 


/* SPORT 2 for TX , frame sync detection - falling edge */

*pSPCTL2 = (SPTRAN | SLEN32 | SCHEN_A | SDEN_A | LMFS );   <---- add |LMFS 


/* enable edge detection for frame sync */ 

*pSPCTLN1 |= FSED;   <---- add | FSED

*pSPCTLN2 |= FSED;   <---- add | FSED


*pSPMCTL1  = NCH15 | MFD0;   <---   before is MFD1, 

*pSPMCTL2  = NCH15 | MFD0;   <---   before is MFD1


     After the change , we tested with a empty schematic ( i.e. input --level detection -- output ) , all 16 channels are still working ( output audio signal is still normal ) but we can see the level detection is indicating at different channel number ( i.e. if we apply audio at input #1 , the level detection module detecting audio signal at input #14 .   When we used the original testing schematic which is working good before,  this schematic  is just adding a gain control in each channel ( i.e. input --> gain control --> level detection ---> output ) . Some of output signal is totally clipped / distorted ( it seems some wrong gain value being applied ) .  Output signal will restore normal only when we set the gain to 0dB other value will distort  the output signal.  Logically the changes are only affect on the SPORT send and receive  TDM data.  I am not sure why such a simple schematic is no longer working .  


      Please let me know urgently if you have any idea about this problem . 


     Thank you very much