I have connected AD9102 to STM32F4Discovery board and i'm using 4-wire spi. When i'm starting to transfer some data there is always 0x0110 on SDO pin and no matter what data on SDIO pin. What does it mean?
Are you trying to read data from a register or performing a write operation when this happens?
It happens always. No matter what is it - read or write operation.
For example, when i'm sending 0x0000 from controller to AD9102, there is 0x0110 on SDO pin.
If i'm trying to read register with address 2Bh, i'm sending 0x802B from controller. On the first 16 clock cycles of SPI, there is also 0x0110 on SDO pin. But on the next 16 clock cycles of SPI, when i should to receive data, there is 0x0110 with high level voltage about 2.7 V instead of 3 V; and there is small increase of voltage in some bits (about 200-300 mV), that repeats reset data of this register (0x0101). See picture below.
Please send a schematic of your interface to the STM32F4.
Retrieving data ...