From a65239957f2152fd799301314190e937f006a712 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Robert=20J=C3=B6rdens?= <rj@quartiq.de>
Date: Thu, 17 Sep 2020 14:13:10 +0000
Subject: [PATCH] ad53xx: distinguish errors

---
 artiq/coredevice/ad53xx.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/artiq/coredevice/ad53xx.py b/artiq/coredevice/ad53xx.py
index c4ff6d3aa..3445555d9 100644
--- a/artiq/coredevice/ad53xx.py
+++ b/artiq/coredevice/ad53xx.py
@@ -178,6 +178,8 @@ class AD53xx:
         self.write_offset_dacs_mu(self.offset_dacs)
         if not blind:
             ctrl = self.read_reg(channel=0, op=AD53XX_READ_CONTROL)
+            if ctrl == 0xffff:
+                raise ValueError("DAC not found")
             if ctrl & 0b10000:
                 raise ValueError("DAC over temperature")
             delay(25*us)