I am having trouble communicating with the AD5421 through SPI. It seems like I am receiving back the exact same instruction I send to the slave device on every transmission (regardless of whether I am trying to read a register or give a write command) and it happens all in one command (as opposed to happening on the subsequent write command).
I am sending 32 bits of data with CRC as the last 8 bits. My first command is to the control register: 0x02F820EC in which I disable the automatic feedback of the fault register. When I send this, I receive the exact same message I just sent: 0x02F820EC.
I then send a command to read back the control register: 0x8200009C, to which I receive the reply: 0x8200009C.
Next, I send a command to the DAC register to output 16mA by sending: 0x01C0005B, and I just receive the exact same message back: 0x01C0005B. If I measure the current it is held low at the fault value of 3.2mA.
Here is a picture of the scope