TAS5766M: Smart Amp exchanges I2S data with master, but no analog audio appears on DAC output

At this point, I don't see anything else I can do but try to get any analog audio signal to get past the DAC & come out of the Smart Amp on our custom board by using the PurePath Console (PPC3) app. Can someone confirm that I can use the PPC3 app connected to my custom target board through a Total Phase Aardvark I2C-to-USB Host Adapter?

Tried connecting the 24.576 MHz oscillator available on power-up directly into TAS5766M's SCK input, instead of 12.288 MHz that starts-up later. No difference in the TAS5766M's behavior: I2S data traffic flows in both directions but no DAC output signal (constant 0 VDC) feeding into built-in power amp (INPR).  Collected some scope captures & register contents after a few thousand samples sent over I2S (see below). Also tried to route some internal signals to GPIO2, giving the following results:

   Page 0 / Register 82 (Hex 0x52)   GPIO2 Output Selection

   These bits select the signal to output to GPIO2. To actually output the selected signal, the GPIO2 must be set to output mode at Page 0 / Register 8.

       Default value: 0000

       0000: off (low)  -->   constant 0V

       0001: DSP GPIO2 output  -->  constant 0V

       0010: Register GPIO2 output (Page 0 / Register 86, bit 2)    -->  sometimes toggled for debugging purposes

       0011: Auto mute flag (asserted when both L and R channels are auto muted)  -->  constant 0V

       0100: Auto mute flag for left channel   -->  constant 0V

       0101: Auto mute flag for right channel   -->   constant 0V

       0110: Clock invalid flag (clock error or clock changing or clock missing)   -->   constant 0V

       0111: Serial audio interface data output (SDOUT)    -->  GPIO3/SDOUT as labelled "DOUT from SA" in scope captures

      1000: Analog mute flag for left channel (low active)   constant ~3.3V

      1001: Analog mute flag for right channel (low active)   constant ~3.3V

      1010: PLL lock flag   -->  constant ~3.3V

      1011: Charge pump clock    -->  1.536 MHz square wave

      1100: DAC clock    -->  6.14 MHz square wave, not sure if 6.14 MHz clock ( = 6 x 1024 kHz BCLK) is correct for DAC

      1101: MiniDSP clock/4    -->   4.10 MHz square wave, not sure if 16.4 MHz clock is correct for miniDSP

      1110: Under voltage flag, asserted when XSMUTE voltage is higher than 0.7 DVDD   -->   constant ~3.3V  ????

      1111: Under voltage flag, asserted when XSMUTE voltage is higher than 0.3 DVDD    -->  constant ~3.3V  ????

As I've said in my original problem description when I opened the case, we know the power-on sequence of Figure 32 is not met because our design connects the TAS5766M's I2S clock inputs to Precision Clock Generator (PCG) block outputs on our DSP, so it doesn’t have SCK, BCK or LRCK upon power-up, but rather not until after the DSP runs to the point it configures its PCG to provide a 12.288 MHz SCK (along with 1024 kHz BCK and 16 kHz LRCK) from a 24.576 MHz external oscillator. We expected to be able to reset the TAS5766M at that point, if it need it.

Taking the TAS5766M into powerdown mode & back out into standby mode has been sufficient to get the TAS5766M to send I2S data (DAC input) back to our DSP on SDOUT/GPIO3, but that restart sequence doesn't seem to allow the DAC to take that input we see on SDOUT/GPIO3 and convert it to an analog signal for the internal amplifier.

Hoped my description was sufficient to give you a clear understanding of what we're doing, but here's a picture of it if it helps.

See additional details I provided above, as requested.

Hi Jean,

How is the TAS5766M device in your design initialized?  Do you feed 4-wire I2S signals (SCLK, BCLK, LRCLK, and DATA) to TAS5766M?

A Total Phase Aardvark I2C-to-USB Host Adapter is not necessary and also it doesn't work with PPC3 GUI.

Try the In-System Tuning mode instead.

Andy

Andy,

Yes, as my original description & the diagram I posted afterward describe, our system provides a common 12.288 MHz master clock to all audio devices on the board, along with a 1024 kHz bit clock and a 16 kHz L/R channel clock to send I2S data to, and receive I2S data from each device.All devices (except input-only devices like microphones which obviously dont have data going to them) have these 5 signals connected. Like my original description says, per your datasheet's Figure 43 "Example Process Flow" on page 32 shows, we've verified there's sample data coming back on GPIO3 (SDOUT) (see the scope capture I provided earlier) so the DAC has data at its input but nothing is coming out of DACR. Again, we're using the TAS5766M in mono mode, just like the datasheet's section 8.2.2 "Mono/PBTL Application" on page 44 describes.  So, my question remains; **** Why is the DACR output at a constant 0V when the DAC inputs show data going to it on both left & right channels, when all the registers I've dumped & the scope outputs don't show any problem aside form the SOF error? ****  Please look at both of these I posted earlier (above) and answer that straight forward question. 

Thank you for confirming that the Total Phase Aardvark I2C-to-USB Host Adapter will not work with PPC3 GUI.