Would you teach about CTRL_DATA, CTRL_CLK, and SYS_MCLK of SGTL5000?
I refer to SPF-26325_b1.pdf of iMX25_PDK_DesignFiles.
According to this schematic, 1.8V is supplied to VDDIO of SGTL5000.
(And 3.3V is supplied to VDDA.)
I understand that digital IO should be 1.8V signal.
However, CTRL_DATA, CTRL_CLK, and SYS_MCLK are 3.3V signals.
I think that these should be 1.8V signals since these signals are digital IO.
Would you teach why these are 3.3V signals?
(Do these signals belong to a VDDA power supply?)