I am confirming how to start and initialize the ADAU1777, ADAU1772 or ADA1372 when an external oscillator is used.
In each data sheet, I can find following description. Regarding it, please let me ask below.
ADAU1772 data sheet (rev.C)
Page 30 CLOCK INITIALIZATION
When a crystal oscillator is used, it is desirable to use a 12.288 MHz crystal, and the crystal oscillator function must be enabled in the COREN bit (Address 0x0000).
The crystal oscillator can be enabled/disabled by the XTAL_DIS bit in the CLK_CONTROL register (Address 0x0000).
Is this understanding correct?
When the external oscillator is connected to the MCLKIN(XTALI),
can the XTAL_DIS be disable (set to 1) to reduce power consumption.
Or must the XTAL_DIS be disabled?
Immediately after power-up, the external oscillator may already provide the MCLK
Then the XTAL_DIS bit is 0 (the internal crystal oscillator is enabled) by default.
Could it cause any problems? After setting the XTAL_DIS into 1, should the MCLK start to be provided?