ad53xx: ignore F3 (reserved)

Signed-off-by: Robert Jördens <[email protected]>

Author: jordens

artiq/coredevice/ad53xx.py

@@ -176,7 +176,7 @@ def init(self, blind=False):
             (AD53XX_CMD_SPECIAL | AD53XX_SPECIAL_CONTROL | 0b0010) << 8)
         if not blind:
             ctrl = self.read_reg(channel=0, op=AD53XX_READ_CONTROL)
-            if ctrl != 0b0010:
+            if (ctrl & 0b10111) != 0b00010:
                 raise ValueError("DAC CONTROL readback mismatch")
             delay(15*us)