urukul/ad9910: support blind init

urukul: always set io_update attribute
to silence compiler warning w.r.t. kernel_invariants

artiq/coredevice/ad9910.py

@@ -57,7 +57,7 @@ class AD9910:
         self.cpld = dmgr.get(cpld_device)
         self.core = self.cpld.core
         self.bus = self.cpld.bus
-        assert 4 <= chip_select <= 7
+        assert 3 <= chip_select <= 7
         self.chip_select = chip_select
         if sw_device:
             self.sw = dmgr.get(sw_device)
@@ -124,21 +124,25 @@ class AD9910:
         self.bus.write(data_low)
 
     @kernel
-    def init(self):
+    def init(self, blind=False):
         """Initialize and configure the DDS.
 
         Sets up SPI mode, confirms chip presence, powers down unused blocks,
         configures the PLL, waits for PLL lock. Uses the
         IO_UPDATE signal multiple times.
+
+        :param blind: Do not read back DDS identity and do not wait for lock.
         """
         # Set SPI mode
         self.write32(_AD9910_REG_CFR1, 0x00000002)
         self.cpld.io_update.pulse(2*us)
-        # Use the AUX DAC setting to identify and confirm presence
+        delay(1*ms)
-        aux_dac = self.read32(_AD9910_REG_AUX_DAC)
+        if not blind:
-        if aux_dac & 0xff != 0x7f:
+            # Use the AUX DAC setting to identify and confirm presence
-            raise ValueError("Urukul AD9910 AUX_DAC mismatch")
+            aux_dac = self.read32(_AD9910_REG_AUX_DAC)
-        delay(50*us)  # slack
+            if aux_dac & 0xff != 0x7f:
+                raise ValueError("Urukul AD9910 AUX_DAC mismatch")
+            delay(50*us)  # slack
         # Configure PLL settings and bring up PLL
         self.write32(_AD9910_REG_CFR2, 0x01400020)
         self.cpld.io_update.pulse(2*us)
@@ -148,6 +152,9 @@ class AD9910:
         self.cpld.io_update.pulse(100*us)
         self.write32(_AD9910_REG_CFR3, cfr3)
         self.cpld.io_update.pulse(100*us)
+        if blind:
+            delay(100*ms)
+            return
         # Wait for PLL lock, up to 100 ms
         for i in range(100):
             sta = self.cpld.sta_read()

artiq/coredevice/urukul.py

@@ -95,6 +95,18 @@ def urukul_sta_proto_rev(sta):
     return (sta >> STA_PROTO_REV) & 0x7f
 
 
+class _RegIOUpdate:
+    def __init__(self, cpld):
+        self.cpld = cpld
+
+    @portable
+    def pulse(self, t):
+        cfg = self.cpld.cfg_reg
+        self.cpld.cfg_write(cfg | (1 << CFG_IO_UPDATE))
+        delay(t)
+        self.cpld.cfg_write(cfg)
+
+
 class CPLD:
     """Urukul CPLD SPI router and configuration interface.
 
@@ -122,6 +134,8 @@ class CPLD:
         self.bus = dmgr.get(spi_device)
         if io_update_device is not None:
             self.io_update = dmgr.get(io_update_device)
+        else:
+            self.io_update = _RegIOUpdate(self)
         if dds_reset_device is not None:
             self.dds_reset = dmgr.get(dds_reset_device)
 
@@ -164,20 +178,23 @@ class CPLD:
         return self.bus.read()
 
     @kernel
-    def init(self):
+    def init(self, blind=False):
         """Initialize and detect Urukul.
 
         Resets the DDS I/O interface and verifies correct CPLD gateware
         version.
         Does not pulse the DDS MASTER_RESET as that confuses the AD9910.
+
+        :param blind: Do not attempt to verify presence and compatibility.
         """
         cfg = self.cfg_reg
         # Don't pulse MASTER_RESET (m-labs/artiq#940)
         self.cfg_reg = cfg | (0 << CFG_RST) | (1 << CFG_IO_RST)
-        proto_rev = urukul_sta_proto_rev(self.sta_read())
+        if not blind:
-        if proto_rev != STA_PROTO_REV_MATCH:
+            proto_rev = urukul_sta_proto_rev(self.sta_read())
-            raise ValueError("Urukul proto_rev mismatch")
+            if proto_rev != STA_PROTO_REV_MATCH:
-        delay(20*us)  # slack, reset
+                raise ValueError("Urukul proto_rev mismatch")
+        delay(100*us)  # reset, slack
         self.cfg_write(cfg)
         delay(1*ms)  # DDS wake up