While trying to use SPI read back functions with my AD5422 (via J8 on the demo kit EVAL-AD5420/22EBZ), the device responds to every register read query with the same incorrect data regardless of which register is being queried.
Query control register (0x020002), response = (0x000001)
Query status register (0x020000), response = (0x000001)
Query data register (0x020001), response = (0x000001)
I know the device is acknowledging the read command as the SDO line leaves tri-state at the rising edge of LATCH following the read command, as described in the data sheet.
I cannot, however, figure out why the data read back is incorrect, or what 0x000001 is supposed to mean to me.
See the attached scope screen grab for the signals:
Ch1 = Master Out
Ch2 = SCLK
Ch3 = Master In
Ch4 = LATCH
Any help is appreciated, and I do not mind feeling like a fool when it's something simple.