AnsweredAssumed Answered

Dolby Digital AC-3 raw bitstream on S/PDIF receiver

Question asked by diego.zallocco on Sep 2, 2011
Latest reply on Nov 16, 2012 by Anil@AMI

Hi all,

I'm trying to test Dolby Digital AC-3 5.1 decoder module from Analog on my ADSP-21469 EZ board.
I would decode a real AC-3 stream: for this I'm using the S/PDIF I connected the audio output of a DVD reader (5.1 raw format).
S/PDIF receiver is routed to SPORT0A:
    // from S/PDIF IN connector
    SRU(LOW, PBEN18_I);
    SRU(DAI_PB18_O, DIR_I);
    // sync and data to SPORT0
    SRU(DIR_CLK_O, SPORT0_CLK_I);
    SRU(DIR_FS_O, SPORT0_FS_I);
    SRU(DIR_DAT_O, SPORT0_DA_I);
What I expect to find is the S/PDIF header frame (I have not the IEC 61937 standard, but I found essential info on the web)
==============================
  HEADER FRAME
    + sync1 = 0xF872
    + sync2 = 0x4E1F
    + type (AC3, DTS, ...)
    + len in bytes
==============================
  AUDIO FRAME
==============================
  ZERO PADDING
==============================
Wich SPORT0 mode should I use?
I tried different configurations (using DMA), but the data do not seem to get correct.
Does anyone have any suggestions?
Regards,
Diego

Outcomes