AD7771 and DOUTx interface

Hi  witc ,

Regarding the data read using SAI- Attached below are the settings with which I was able to get the data read successfully

Init:

Thank you!

Now I can read the data by STM32!! BUT: I had to change some params:

1) ClockStrobing to 0 - Data are sampled on Falling edge - datsheet page 9, Figure 2

2) ActiveFrameLength to 128 - not exactly sure why has to be this value

Could you check if the DOUT_FORMAT[7:6] in the DOUT_FORMAT register (Address- 0x14) is set to 10 or 11 to get all data on a single DOUT line?

Reference: Datasheet - page 74

www.analog.com/.../ad7771.pdf

I set bits [7:6] to 0b11 

Exactly this:

uint8_t tmp = 0;

AD771_ReadFromReg(0x14, &tmp, 1);

tmp |= (1<<7) | (1<<6); //1 out line for all channels
tmp &=~ (1<<5); //status header
tmp |= (4<<1); //DCLK

AD771_WriteToReg(0x14,&tmp,1);

Also I was probably in a hurry. I can read now only first 4 channels. But I'm pretty sure I could read all 8 channels - so had to change something else... 

Hi witc ,

I hope you have got answers for all the queries you had. Please confirm that you could read all 8 channels.

Thanks

Vikas J

Hi, unfortunatelly I can not confirm it.

The best results  I have got:

I Can read 4 channels or can read 8 channels but with shift: first byte is on second possition in my rxDataArray,... so I need to read not 32 bytes but 33. So I still do not have the right configuration, cannot find any detailed information about it

Hi, unfortunatelly I can not confirm it.

The best results  I have got:

I Can read 4 channels or can read 8 channels but with shift: first byte is on second possition in my rxDataArray,... so I need to read not 32 bytes but 33. So I still do not have the right configuration, cannot find any detailed information about it

Finally!

This variant works to me - reading 8 channels in 1 DOUt line:

hsai_BlockB3.Instance = SAI3_Block_B;
  hsai_BlockB3.Init.Protocol = SAI_FREE_PROTOCOL;
  hsai_BlockB3.Init.AudioMode = SAI_MODESLAVE_RX;
  hsai_BlockB3.Init.DataSize = SAI_DATASIZE_32;
  hsai_BlockB3.Init.FirstBit = SAI_FIRSTBIT_MSB;
  hsai_BlockB3.Init.ClockStrobing = SAI_CLOCKSTROBING_FALLINGEDGE;
  hsai_BlockB3.Init.Synchro = SAI_ASYNCHRONOUS;
  hsai_BlockB3.Init.OutputDrive = SAI_OUTPUTDRIVE_DISABLE;
  hsai_BlockB3.Init.FIFOThreshold = SAI_FIFOTHRESHOLD_EMPTY;
  hsai_BlockB3.Init.SynchroExt = SAI_SYNCEXT_DISABLE;
  hsai_BlockB3.Init.MonoStereoMode = SAI_STEREOMODE;
  hsai_BlockB3.Init.CompandingMode = SAI_NOCOMPANDING;
  hsai_BlockB3.Init.TriState = SAI_OUTPUT_NOTRELEASED;
  hsai_BlockB3.Init.PdmInit.Activation = DISABLE;
  hsai_BlockB3.Init.PdmInit.MicPairsNbr = 1;
  hsai_BlockB3.Init.PdmInit.ClockEnable = SAI_PDM_CLOCK1_ENABLE;
  hsai_BlockB3.FrameInit.FrameLength = 256;
  hsai_BlockB3.FrameInit.ActiveFrameLength = 1;
  hsai_BlockB3.FrameInit.FSDefinition = SAI_FS_STARTFRAME;
  hsai_BlockB3.FrameInit.FSPolarity = SAI_FS_ACTIVE_LOW;
  hsai_BlockB3.FrameInit.FSOffset = SAI_FS_FIRSTBIT;
  hsai_BlockB3.SlotInit.FirstBitOffset = 0;
  hsai_BlockB3.SlotInit.SlotSize = SAI_SLOTSIZE_32B;
  hsai_BlockB3.SlotInit.SlotNumber = 8;
  hsai_BlockB3.SlotInit.SlotActive = SAI_SLOTACTIVE_0|SAI_SLOTACTIVE_1|SAI_SLOTACTIVE_2|SAI_SLOTACTIVE_3
		  	  	  	  	  	  	  	  |SAI_SLOTACTIVE_4|SAI_SLOTACTIVE_5|SAI_SLOTACTIVE_6|SAI_SLOTACTIVE_7;

Thank you all!