m-labs · Mar 3, 2016 · Mar 3, 2016
Showing with 103 additions and 74 deletions.

+95 −0 artiq/coredevice/ad5360.py

+0 −71 artiq/coredevice/ad53xx.py

+3 −3 artiq/coredevice/spi.py

+5 −0 doc/manual/core_drivers_reference.rst
diff --git a/artiq/coredevice/ad5360.py b/artiq/coredevice/ad5360.py
@@ -0,0 +1,95 @@
+from artiq.language.core import kernel, portable, delay
+from artiq.language.units import ns
+from artiq.coredevice import spi
+
+
+_AD5360_SPI_CONFIG = (0*spi.SPI_OFFLINE | 0*spi.SPI_CS_POLARITY |
+                      0*spi.SPI_CLK_POLARITY | 1*spi.SPI_CLK_PHASE |
+                      0*spi.SPI_LSB_FIRST | 0*spi.SPI_HALF_DUPLEX)
+
+_AD5360_CMD_DATA = 3 << 22
+_AD5360_CMD_OFFSET = 2 << 22
+_AD5360_CMD_GAIN = 1 << 22
+_AD5360_CMD_SPECIAL = 0 << 22
+
+
+@portable
+def _AD5360_WRITE_CHANNEL(c):
+    return (c + 8) << 16
+
+_AD5360_SPECIAL_NOP = 0 << 16
+_AD5360_SPECIAL_CONTROL = 1 << 16
+_AD5360_SPECIAL_OFS0 = 2 << 16
+_AD5360_SPECIAL_OFS1 = 3 << 16
+_AD5360_SPECIAL_READ = 3 << 16
+
+
+@portable
+def _AD5360_READ_CHANNEL(ch):
+    return (ch + 8) << 7
+
+_AD5360_READ_X1A = 0x000 << 7
+_AD5360_READ_X1B = 0x040 << 7
+_AD5360_READ_OFFSET = 0x080 << 7
+_AD5360_READ_GAIN = 0x0c0 << 7
+_AD5360_READ_CONTROL = 0x101 << 7
+_AD5360_READ_OFS0 = 0x102 << 7
+_AD5360_READ_OFS1 = 0x103 << 7
+
+
+class AD5360:
+    """
+    Support for the Analog devices AD53[67][0123]
+    multi-channel Digital to Analog Converters
+    """
+
+    def __init__(self, dmgr, spi_bus, ldac=None, chip_select=0):
+        self.core = dmgr.get("core")
+        self.bus = dmgr.get(spi_bus)
+        if ldac is not None:
+            ldac = dmgr.get(ldac)
+        self.ldac = ldac
+        self.chip_select = chip_select
+
+    @kernel
+    def setup_bus(self, write_div=4, read_div=7):
+        # write: 2*8ns >= 10ns = t_6 (clk falling to cs_n rising)
+        # read: 4*8*ns >= 25ns = t_22 (clk falling to miso valid)
+        self.bus.set_config_mu(_AD5360_SPI_CONFIG, write_div, read_div)
+        self.bus.set_xfer(self.chip_select, 24, 0)
+
+    @kernel
+    def write_offsets(self, value=0x1fff):
+        value &= 0x3fff
+        self.bus.write((_AD5360_CMD_SPECIAL | _AD5360_SPECIAL_OFS0 | value
+                        ) << 8)
+        self.bus.write((_AD5360_CMD_SPECIAL | _AD5360_SPECIAL_OFS1 | value
+                        ) << 8)
+
+    @kernel
+    def write_channel(self, channel=0, value=0, op=_AD5360_CMD_DATA):
+        channel &= 0x3f
+        value &= 0xffff
+        self.bus.write((op | _AD5360_WRITE_CHANNEL(channel) | value) << 8)
+
+    @kernel
+    def write_channels(self, values, first=0, op=_AD5360_CMD_DATA):
+        for i in range(len(values)):
+            self.write_channel(i + first, values[i], op)
+
+    @kernel
+    def read_channel_sync(self, channel=0, op=_AD5360_READ_X1A):
+        channel &= 0x3f
+        self.bus.write((_AD5360_CMD_SPECIAL | _AD5360_SPECIAL_READ | op |
+                        _AD5360_READ_CHANNEL(channel)) << 8)
+        self.bus.set_xfer(self.chip_select, 0, 24)
+        self.bus.write((_AD5360_CMD_SPECIAL | _AD5360_SPECIAL_NOP) << 8)
+        self.bus.read_async()
+        self.bus.set_xfer(self.chip_select, 24, 0)
+        return self.bus.input_async() & 0xffff
+
+    @kernel
+    def load(self):
+        self.ldac.off()
+        delay(24*ns)
+        self.ldac.on()
diff --git a/artiq/coredevice/ad53xx.py b/artiq/coredevice/ad53xx.py
diff --git a/artiq/coredevice/spi.py b/artiq/coredevice/spi.py
@@ -198,11 +198,11 @@ def write(self, data=0):
           the previous transfer's read data is available in the
           ``data`` register.
 
-        This method advances the timeline by the duration of the
-        RTIO-to-Wishbone bus transaction (three RTIO clock cycles).
+        This method advances the timeline by the duration of the SPI transfer.
+        If a transfer is to be chained, the timeline needs to be rewound.
         """
         rtio_output(now_mu(), self.channel, SPI_DATA_ADDR, data)
-        delay_mu(3*self.ref_period_mu)
+        delay_mu(self.xfer_period_mu + self.write_period_mu)
 
     @kernel
     def read_async(self):

diff --git a/doc/manual/core_drivers_reference.rst b/doc/manual/core_drivers_reference.rst
@@ -30,6 +30,11 @@ These drivers are for the core device and the peripherals closely integrated int
 .. automodule:: artiq.coredevice.spi
     :members:
 
+:mod:`artiq.coredevice.ad5360` module
+-------------------------------------
+
+.. automodule:: artiq.coredevice.ad5360
+    :members:
 
 :mod:`artiq.coredevice.exceptions` module
 -----------------------------------------