I'm interfacing to an AD5420 via 1Mbps SPI. When reading back the Control, Data, and Status registers, the Control and Status registers return the expected values, but the Data register returns a constant 0x0400 regardless of what value is written. The current output is correct. I have the Range bits set to 110, and a Data value of 0x8000 produces 10mA, 0xC000 produces 15mA, etc.
When initially integrating my software, the data register readback worked normally (I saw the value previously written), but now all I get is 0x0400.
I'm seeing the same behavior on two different boards. The constant value returned from the Data register is different between the two (The other board is reading back 0x3C0), but the behavior is the same.