diff --git a/artiq/coredevice/ad9910.py b/artiq/coredevice/ad9910.py
index 4d4399b82..c3263acce 100644
--- a/artiq/coredevice/ad9910.py
+++ b/artiq/coredevice/ad9910.py
@@ -44,7 +44,7 @@ class AD9910:
         self.cpld = dmgr.get(cpld_device)
         self.core = self.cpld.core
         self.bus = self.cpld.bus
-        assert chip_select >= 4
+        assert 4 <= chip_select <= 7
         self.chip_select = chip_select
         if sw_device:
             self.sw = dmgr.get(sw_device)
@@ -61,13 +61,12 @@ class AD9910:
         self.pll_cp = pll_cp
 
     @kernel
-    def write(self, addr, data, length=4):
-        assert (length == 2) or (length == 4)
+    def write32(self, addr, data):
         self.bus.set_xfer(self.chip_select, 8, 0)
         self.bus.write(addr << 24)
         delay_mu(-self.bus.xfer_period_mu)
-        self.bus.set_xfer(self.chip_select, length*8, 0)
-        self.bus.write(data << (32 - length*8))
+        self.bus.set_xfer(self.chip_select, 32, 0)
+        self.bus.write(data)
         delay_mu(self.bus.xfer_period_mu - self.bus.write_period_mu)
 
     @kernel
@@ -82,36 +81,32 @@ class AD9910:
         delay_mu(t - 2*self.bus.write_period_mu)
 
     @kernel
-    def read(self, addr, length=4):
-        assert length >= 2
-        assert length <= 4
+    def read32(self, addr):
         self.bus.set_xfer(self.chip_select, 8, 0)
         self.bus.write((addr | 0x80) << 24)
         delay_mu(-self.bus.xfer_period_mu)
-        self.bus.set_xfer(self.chip_select, 0, length*8)
+        self.bus.set_xfer(self.chip_select, 0, 32)
         self.bus.write(0)
         delay_mu(2*self.bus.xfer_period_mu)
         data = self.bus.read_sync()
-        if length < 4:
-            data &= (1 << (length*8)) - 1
         return data
 
     @kernel
     def init(self):
-        # self.cpld.io_rst()
-        self.write(_AD9910_REG_CFR1, 0x00000002)
+        self.write32(_AD9910_REG_CFR1, 0x00000002)
         delay(100*ns)
         self.cpld.io_update.pulse(100*ns)
-        aux_dac = self.read(_AD9910_REG_AUX_DAC)
-        assert aux_dac & 0xff == 0x7f
+        aux_dac = self.read32(_AD9910_REG_AUX_DAC)
+        if aux_dac & 0xff != 0x7f:
+            raise ValueError("Urukul AD9910 AUX_DAC mismatch")
         delay(10*us)
-        self.write(_AD9910_REG_CFR2, 0x01400020)
+        self.write32(_AD9910_REG_CFR2, 0x01400020)
         cfr3 = (0x0807c100 | (self.pll_vco << 24) |
                 (self.pll_cp << 19) | (self.pll_n << 1))
-        self.write(_AD9910_REG_CFR3, cfr3 | 0x400)  # PFD reset
+        self.write32(_AD9910_REG_CFR3, cfr3 | 0x400)  # PFD reset
         delay(10*us)
         self.cpld.io_update.pulse(100*ns)
-        self.write(_AD9910_REG_CFR3, cfr3)
+        self.write32(_AD9910_REG_CFR3, cfr3)
         delay(10*us)
         self.cpld.io_update.pulse(100*ns)
         for i in range(100):
diff --git a/artiq/coredevice/ad9912.py b/artiq/coredevice/ad9912.py
index 77e78d568..a5da146ed 100644
--- a/artiq/coredevice/ad9912.py
+++ b/artiq/coredevice/ad9912.py
@@ -21,7 +21,7 @@ class AD9912:
         self.cpld = dmgr.get(cpld_device)
         self.core = self.cpld.core
         self.bus = self.cpld.bus
-        assert chip_select >= 4
+        assert 4 <= chip_select <= 7
         self.chip_select = chip_select
         if sw_device:
             self.sw = dmgr.get(sw_device)
@@ -60,7 +60,8 @@ class AD9912:
         t = now_mu()
         self.write(AD9912_SER_CONF, 0x99)
         prodid = self.read(AD9912_PRODIDH, length=2)
-        assert (prodid == 0x1982) or (prodid == 0x1902)
+        if (prodid != 0x1982) and (prodid != 0x1902):
+            raise ValueError("Urukul AD9912 product id mismatch")
         delay(10*us)
         self.write(AD9912_PWRCNTRL1, 0x80)  # HSTL, CMOS power down
         delay(10*us)
diff --git a/artiq/coredevice/urukul.py b/artiq/coredevice/urukul.py
index 28f31f7a5..c905d7441 100644
--- a/artiq/coredevice/urukul.py
+++ b/artiq/coredevice/urukul.py
@@ -1,5 +1,5 @@
 from artiq.language.core import kernel, delay_mu, delay, now_mu, at_mu
-from artiq.language.units import us
+from artiq.language.units import us, ms
 
 from numpy import int32, int64
 
@@ -126,8 +126,9 @@ class CPLD:
             io_update=0, mask_nu=0, clk_sel=clk_sel,
             sync_sel=sync_sel, rst=0, io_rst=0)
         self.cfg_write(cfg | (1 << CFG_RST) | (1 << CFG_IO_RST))
-        delay(100*us)
+        delay(1*ms)
         self.cfg_write(cfg)
+        delay(10*ms)  # DDS wake up
         proto_rev = urukul_sta_proto_rev(self.sta_read())
         if proto_rev != STA_PROTO_REV_MATCH:
             raise ValueError("Urukul proto_rev mismatch")
diff --git a/artiq/examples/master/repository/coredevice_examples/simple/urukul.py b/artiq/examples/master/repository/coredevice_examples/simple/urukul.py
index b89deb2bb..42454b36b 100644
--- a/artiq/examples/master/repository/coredevice_examples/simple/urukul.py
+++ b/artiq/examples/master/repository/coredevice_examples/simple/urukul.py
@@ -29,7 +29,6 @@ class UrukulTest(EnvExperiment):
         self.led.off()
 
         self.urukul_cpld.init(clk_sel=1)
-        delay(1*ms)  # DDS wake up
         self.urukul_ch0b.init()
         self.urukul_ch1b.init()
         self.urukul_ch2b.init()