I understand that CPOL takes effect only after SPE is set. But when I talks with AD7606, I need to have CPOL high at idle, and one line only(either BIDIMODE=0 or BIDIMODE=1) for receiving. In this mode, SPE can only be set after NSS is pulled low and that's when the receiving can start. Well now I cannot have SCK high before NSS low and that makes the timing wrong.
Yes I can utilize the full duplex mode and always have SPE set, which makes correct timing. But the transmit line is wasted this way because it's not needed.
Is there a perfect way to talk with this kind of device, which requires SCK high at idle and only a receiving line is used?