Hi,
In one of our project, we selected AD7764 ADC. Now we are designing the interface circuit.Compared to other SPI ADCs, AD7764 have a very complicated SPI interface. One best thing we select in this is, it is always a MASTER SPI.
SCO(O), FSO(O), SDO(O), FSI(I), SDI(I) are the SPI signals available.Since CLK i.e.SCO is driven by AD7764, we configure our MCU as Slave. SCO is connected to SCLK, FSO is connected to CS, SDO is connected to MOSI. With this configuration, data read is fine, but the issue in Writing Data to Control register. Do the MCU need to be a Master while writing the data? If yes, with the same SPI or with other SPI port? or can we simply managed the writing signals (FSI & SDI) with GPIO pins? We are also using digital isolators in between the interface. Please find the block diag in the attachment. Please advice how to configure the SDI and FSI signals and the interfacing approaches.
Thanks in advance