I need to implement loading of ADAU1701 DSP program via SPI control port. I have microcontroller code that takes the CLATCH pin lo-high 3x to put the device in SPI mode, and I have verified that the timing and format of SPI is correct, as described in the SPI PORT section (p. 27) of the ADAU1701 data sheet. I followed the procedure to port the files from SigmaStudio and integrated them into my uC code. However this does not work on either the EVAL-ADAU1701MINIZ or a custom 1701 board I have.
I can, however, program both targets using the USBi, which uses I2C mode. After a bit of searching on the forum and re-reading the data sheets, I suspect that the reason why I cannot boot using uC with SPI is that the SELFBOOT pin is tied high on the 2 boards I'm working with and it must be low for control port to be enabled. This is indicated in the 1701 data sheet p. 23 and in the schematics at the end of the data sheet ( pp. 51-52) Could someone please verify this?
However, if SELFBOOT is required to be low for the control port to work, how is SigmaStudio able to load a program via the USBi when SELFBOOT is tied high on the EVAL-ADAU1701MINIZ? Further to this point, I have read in this forum that the USBi can work in I2C mode but not in SPI mode. Can anyone else shed some light here?