On page 30, the AD4000/4004/4008 datasheet says this about 3-Wire Without Busy Indicator mode, "When performing conversions in this mode, SDI must be held high." But on the same page, under Figure 53, it says "SDI must be connected to the digital host data out to write to the configuration register." This seems like a contradiction; could anyone please provide an answer to these questions I have?
1. Does sending the register access command and the register data on SDI prevent a normal conversion from occurring? In other words, must I send the configuration data once before use, and then keep SDI high during normal ADC conversion operation?
2. How does the AD4000 determine whether it is in register read/write mode, 3-wire mode, or 4-wire mode? Is it done by the during that CNV is held high? I.e. minimum time results in register read/write mode, a medium time results in 3-wire mode, and a long time results in 4-wire mode?