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The WM8804 looks like the ideal candidate for a design I'm working on --- this single chip could replace the need for one receiver and one transmitter. The specific routing requirements are:

I need one of the following two configurations, selectable "on-the-fly", during operation (say, a switch that a microcontroller reads, and the microcontroller uses GPIO pins to control and reconfigure the WM8804):

  • I2S input → route to SPDIF output
  • SPDIF input → route to both I2S output and SPDIF output

Table 15 on page 20 and Figure 15 on page 20 of the WM8804 datasheet suggest that it can do that: TXSRC selects the source for the SPDIF transmitter; the diagram in Figure 15 shows that the output of SPDIF RX goes to both the I2S and the SPDIF transmitter; if I set, in hardware/standalone mode, CSB = 0 (corresponding to TXSRC = SPDIF RX), the multiplexer will select SPDIF RX as the source for SPDIF TX, but SPDIF RX will also go to the I2S decoder and ultimately DOUT.

I have had enough ugly surprises with datasheets' misinformation (or hidden information, especially about limitations of the device) that I'm paranoid enough and would like to ask:

Anyone out there has tried this or similar configurations with the WM8804 and can confirm that this is the case?

In case this makes a difference: please notice, although I'll have a microcontroller on the same board, I really, really prefer to use the WM8804 in standalone/hardware mode; even if the microcontroller will drive the few pins that the WM8804 will read at startup to determine its configuration.

Cal-linux
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  • You aren't really focusing on a proper EE question - I'm sure there are folk out there but you are just going to get opinions and they aren't really valid for this site. – Andy aka Jul 02 '19 at 07:13
  • Not sure why you expect that this question will only get opinions. There's a specific, objective characteristic of this device that my design depends on, and I'm hoping that people that have used the chip will know the answer for sure; I give you that I may get answers along the lines of: "the datasheet says 'the chip does X', why would you ask us whether the chip does X or Y?" --- that's why the clarification about my recent experiences with datasheets doing a truly lousy job at making it clear what the device does or doesn't do. – Cal-linux Jul 02 '19 at 11:48

1 Answers1

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Digging some more, I found this other electronics.SE post that answers my question (in passing, but still explicitly). The answer being: yes, the WM8804 does as indicated in the datasheet, Figure 15.

Cal-linux
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