CC3200: how to disable McAFSx in I2S

Hi Jack,

If you want to use an I2S-like interface to transport data that's not audio, you should probably be using the SPI peripheral, and not the I2S peripheral.

The SPI peripheral on the CC3200 is much more configurable than the I2S. Like I2S, you have 4 signals (clk, chip select/frame sync, data in, data out). With SPI, you can either let the peripheral handle the assertion of the CS signal at a hardware level automatically, at the software level where you assert it by toggling a control bit in one of the SPI control register, or remove control of CS from the SPI peripheral entirely and just use a GPIO toggle.

Let me know if you need more details on how to setup the SPI interface to suit your use case.

If you want to keep using the I2S peripheral, you should take a look at section 12.5 of the TRM to see which registers might allow you to turn off the McAFSx while still keeping the data transmission:www.ti.com/.../swru465.pdf
This is the TRM for the CC3220, but the I2S peripheral should be similar to the CC3200 that the register mapping is valid. In particular, you might want to try disabling the McAFSx generator. You can look at i2s.c of the driverlib for how to access and set bits in the I2S peripherals.

Regards,
Michael