pdq2: driver and unittest

* parses wavesynth style programs
* verified with cosimulated gateware

artiq/devices/pdq2/driver.py

@@ -1,38 +1,45 @@
 # Robert Jordens <jordens@gmail.com>, 2012-2015
 
+from math import log2, sqrt
 import logging
 import struct
-import warnings
 
-import numpy as np
-from scipy import interpolate
 import serial
 
 logger = logging.getLogger(__name__)
 
 
 class Segment:
+    max_time = 1 << 16  # uint16 timer
+    max_val = 1 << 15  # int16 DAC
+    max_out = 10. # Volt
+    out_scale = max_val/max_out
+    cordic_gain = 1.
+    for i in range(16):
+        cordic_gain *= sqrt(1 + 2**(-2*i))
+
     def __init__(self):
         self.data = b""
 
-    def line(self, typ, dt, data, trigger=False, silence=False,
+    def line(self, typ, duration, data, trigger=False, silence=False,
-             aux=False, shift=0, end=False, clear=False, wait=False):
+             aux=False, shift=0, jump=False, clear=False, wait_trigger=False):
         assert len(data) % 2 == 0, data
         assert len(data)//2 <= 14
         #assert dt*(1 << shift) > 1 + len(data)//2
-        head = (
+        header = (
             1 + len(data)//2 | (typ << 4) | (trigger << 6) | (silence << 7) |
-            (aux << 8) | (shift << 9) | (end << 13) | (clear << 14) |
+            (aux << 8) | (shift << 9) | (jump << 13) | (clear << 14) |
-            (wait << 15)
+            (wait_trigger << 15)
         )
-        self.data += struct.pack("<HH", head, dt) + data
+        self.data += struct.pack("<HH", header, duration) + data
 
     @staticmethod
     def pack(widths, values):
         fmt = "<"
         ud = []
         for width, value in zip(widths, values):
-            if width == 3:
+            value = int(round(value * (1 << 16*width)))
+            if width == 2:
                 ud.append(value & 0xffff)
                 fmt += "H"
                 value >>= 16
@@ -42,96 +49,40 @@ class Segment:
         try:
             return struct.pack(fmt, *ud)
         except struct.error as e:
-            logger.error("%s as %s: %s", ud, fmt, e)
+            logger.error("can not pack %s as %s (%s as %s): %s",
+                         values, widths, ud, fmt, e)
             raise e
 
-    def lines(self, typ, dt, widths, v, first={}, mid={}, last={}, shift=0):
-        n = len(dt) - 1
-        dt = dt.astype(np.uint16)
-        v = v.astype(np.int64)
-        for i, (dti, vi) in enumerate(zip(dt, v)):
-            opts = mid
-            if i == 0:
-                opts = first
-            elif i == n:
-                opts = last
-            data = self.pack(widths, vi)
-            self.line(typ, dti, data, shift=shift, **opts)
-
     @staticmethod
-    def interpolate(t, v, order, t_eval, widths=None):
+    def compensate(coef):
-        """Spline interpolating derivatives for t,v.
+        """compensates higher order spline coefficients for integrator chain
-        The returned spline coefficients are one shorter than t
+        latency"""
-        """
+        order = len(coef)
-        if order == 0:
-            return np.rint(v[:, None])
-        # FIXME: does not ensure that interpolates do not clip
-        s = interpolate.splrep(t, v, k=order)
-        # FIXME: needs k knots outside t_eval
-        # dv = np.array(interpolate.spalde(t_eval, s))
-        dv = np.array([interpolate.splev(t_eval, s, der=i, ext=0)
-                       for i in range(order + 1)]).T
-        # correct for adder chain latency
-        if order > 1:
-            dv[:, 1] += dv[:, 2]/2
         if order > 2:
-            dv[:, 1] += dv[:, 3]/6
+            coef[1] += coef[2]/2.
-            dv[:, 2] += dv[:, 3]
+        if order > 3:
-        if widths is not None:
+            coef[1] += coef[3]/6.
-            dv *= 1 << 16*widths
+            coef[2] += coef[3]
-        return np.rint(dv)
+        return coef
 
-    def line_times(self, t, tr=None):
+    def bias(self, amplitude=[], **kwargs):
-        if tr is None:
+        coef = self.compensate([self.out_scale*a for a in amplitude])
-            tr = np.rint(t)
+        data = self.pack([0, 1, 2, 2], coef)
-        if len(tr) == 1:
+        self.line(typ=0, data=data, **kwargs)
-            return None, np.array([1])
-        dt = np.diff(tr)
-        assert np.all(dt >= 0)
-        assert np.all(dt < (1 << 16))
-        return tr[:-1], dt
 
-    def dac(self, t, v, first={}, mid={}, last={},
+    def dds(self, amplitude=[], phase=[], **kwargs):
-            shift=0, tr=None, order=3, stop=True):
+        scale = self.out_scale/self.cordic_gain
-        widths = np.array([1, 2, 3, 3])
+        coef = self.compensate([scale*a for a in amplitude])
-        tr, dt = self.line_times(t, tr)
+        if phase:
-        dv = self.interpolate(t, v, order, tr, widths[:order + 1] - 1)
+            assert len(amplitude) == 4
-        self.lines(0, dt, widths, dv, first, mid, mid if stop else last, shift)
+        coef += [p*self.max_val for p in phase]
-        if stop:
+        data = self.pack([0, 1, 2, 2, 0, 1, 1], coef)
-            self.line(0, 2, self.pack([1], [int(round(v[-1]))]), **last)
+        self.line(typ=1, data=data, **kwargs)
-
-    def dds(self, t, v, p=None, f=None, first={}, mid={}, last={},
-            shift=0, tr=None, order=3, stop=True):
-        widths = np.array([1, 2, 3, 3, 1, 2, 2])
-        tr, dt = self.line_times(t, tr)
-        dv = self.interpolate(t, v, order, tr, widths[:order + 1] - 1)
-        if p is not None:
-            assert order == 3
-            dp = self.interpolate(t, p, 1, tr)[:, :1]
-            dv = np.concatenate((dv, dp), axis=1)
-            if f is not None:
-                df = self.interpolate(t, f, 1, tr, widths[-2:] - 1)
-                dv = np.concatenate((dv, df), axis=1)
-        self.lines(1, dt, widths, dv, first, mid, mid if stop else last, shift)
-        if stop:
-            dv = [int(round(v[-1])), 0, 0, 0]
-            if p is not None:
-                dv.append(int(round(p[-1])))
-                if f is not None:
-                    dv.append(int(round(f[-1])))
-            self.line(1, 2, self.pack(widths, dv), **last)
 
 
 class Channel:
-    max_data = 4*(1 << 10)  # 8kx16 8kx16 4kx16
     num_frames = 8
-    max_val = 1 << 15  # int16 bit DAC
+    max_data = 4*(1 << 10)  # 8kx16 8kx16 4kx16
-    max_time = 1 << 16  # uint16 bit timer
-    cordic_gain = 1.
-    for i in range(16):
-        cordic_gain *= np.sqrt(1 + 2**(-2*i))
-    max_out = 10.
-    freq = 50e6  # samples/s
 
     def __init__(self):
         self.segments = []
@@ -145,29 +96,6 @@ class Channel:
         self.segments.append(segment)
         return segment
 
-    def segment(self, t, v, p=None, f=None,
-                order=3, aux=False, shift=0, trigger=True, end=True,
-                silence=False, stop=True, clear=True, wait=False):
-        segment = self.new_segment()
-        t = t*(self.freq/2**shift)
-        v = np.clip(v/self.max_out, -1, 1)
-        order = min(order, len(t) - 1)
-        first = dict(trigger=trigger, clear=clear, aux=aux)
-        mid = dict(aux=aux)
-        last = dict(silence=silence, end=end, wait=wait, aux=aux)
-        if p is None:
-            v = v*self.max_val
-            segment.dac(t, v, first, mid, last, shift=shift, order=order,
-                        stop=stop)
-        else:
-            v = v*(self.max_val/self.cordic_gain)
-            p = p*(self.max_val/np.pi)
-            if f is not None:
-                f = f*(self.max_val/self.freq)
-            segment.dds(t, v, p, f, first, mid, last, shift=shift,
-                        order=order, stop=stop)
-        return segment
-
     def place(self):
         addr = self.num_frames
         for segment in self.segments:
@@ -196,27 +124,26 @@ class Pdq2:
     PDQ DAC (a.k.a. QC_Waveform)
     """
     num_dacs = 3
-    num_boards = 3
-    num_channels = num_dacs*num_boards
 
     _escape = b"\xa5"
     _commands = "RESET TRIGGER ARM DCM START".split()
 
-    def __init__(self, url=None, dev=None):
+    def __init__(self, url=None, dev=None, num_boards=3):
         if dev is None:
             dev = serial.serial_for_url(url)
         self.dev = dev
+        self.num_boards = num_boards
+        self.num_channels = self.num_dacs * self.num_boards
         self.channels = [Channel() for i in range(self.num_channels)]
-        self.set_freq()
-
-    def set_freq(self, f=50e6):
-        for c in self.channels:
-            c.freq = f
 
     def close(self):
         self.dev.close()
         del self.dev
 
+    def clear_all(self):
+        for channel in self.channels:
+            channel.clear()
+
     def write(self, data):
         logger.debug("> %r", data)
         written = self.dev.write(data)
@@ -236,29 +163,41 @@ class Pdq2:
         data = data.replace(self._escape, self._escape + self._escape)
         self.write(data)
 
-    def write_channel(self, channel, entry=None):
+    def write_channel(self, channel):
         self.write_mem(self.channels.index(channel),
-                       channel.serialize(entry))
+                       channel.serialize())
 
     def write_all(self):
         for channel in self.channels:
             self.write_mem(self.channels.index(channel),
                            channel.serialize())
 
-    def write_table(self, channel, segments=None):
+    def write_table(self, channel):
         # no segment placement
         # no segment writing
-        self.write_mem(channel, self.channels[channel].table(segments))
+        self.write_mem(channel, self.channels[channel].table())
 
     def write_segment(self, channel, segment):
         # no collision check
         s = self.channels[channel].segments[segment]
         self.write_mem(channel, s.data, s.adr)
 
-    def multi_segment(self, times_voltages, channel, map=None, **kwargs):
+    def program(self, program):
-        warnings.warn("deprecated", DeprecationWarning)
+        self.clear_all()
-        c = self.channels[channel]
+        for segment_data in program:
-        del c.segments[:]
+            segments = [c.new_segment() for c in self.channels]
-        for t, v in times_voltages:
+            for line in segment_data:
-            c.segment(t, v, **kwargs)
+                dac_divider = line.get("dac_divider", 1)
-        return c.serialize(map)
+                shift = int(log2(dac_divider))
+                assert 2**shift == dac_divider
+                duration = line["duration"]
+                jump = line.get("jump", False)
+                wait_trigger = line.get("wait_trigger", False)
+                for segment, data in zip(segments, line.get("channel_data")):
+                    assert len(data) == 1
+                    for target, target_data in data.items():
+                        getattr(segment, target)(
+                            shift=shift, duration=duration,
+                            wait_trigger=wait_trigger, jump=jump,
+                            **target_data)
+        self.write_all()

artiq/test/pdq2.py

@@ -0,0 +1,92 @@
+import unittest
+import os
+import io
+
+from artiq.devices.pdq2.driver import Pdq2
+
+
+no_hardware = bool(os.getenv("ARTIQ_NO_HARDWARE")) \
+    or bool(os.getenv("ARTIQ_NO_PERIPHERALS"))
+
+pdq2_source = os.getenv("ARTIQ_PDQ2_SOURCE")
+
+
+class TestPdq2(unittest.TestCase):
+    def setUp(self):
+        self.dev = Pdq2(dev=io.BytesIO())
+
+    def test_reset(self):
+        self.dev.cmd("RESET", True)
+        buf = self.dev.dev.getvalue()
+        self.assertEqual(buf, b"\xa5\x00")
+
+    def test_program(self):
+        self.dev.program(_test_program)
+
+    @unittest.skipUnless(pdq2_source, "no pdq2 source and gateware")
+    def test_gateware(self):
+        self.dev.cmd("START", False)
+        self.dev.cmd("ARM", False)
+        self.dev.program(_test_program)
+        self.dev.cmd("START", True)
+        self.dev.cmd("ARM", True)
+        #self.dev.cmd("TRIGGER", True)
+        buf = self.dev.dev.getvalue()
+        import sys
+        sys.path.append(pdq2_source)
+        from gateware.pdq2 import Pdq2Sim
+        from migen.sim.generic import run_simulation
+        from matplotlib import pyplot as plt
+        import numpy as np
+        tb = Pdq2Sim(buf)
+        tb.ctrl_pads.trigger.reset = 0
+        run_simulation(tb, vcd_name="pdq2.vcd", ncycles=700)
+        out = np.array(tb.outputs, np.uint16).view(np.int16)
+        for outi in out[len(buf):].T:
+            plt.step(np.arange(len(outi)), outi)
+        plt.show()
+
+
+_test_program = [
+    [
+        {
+            "duration": 20,
+            "channel_data": [
+                {"bias": {"amplitude": [0, 0, 2e-3]}},
+                {"bias": {"amplitude": [1, 0, -7.5e-3, 7.5e-4]}},
+                {"dds": {
+                    "amplitude": [0, 0, 4e-3, 0],
+                    "phase": [.5, .05],
+                }},
+            ],
+        },
+        {
+            "duration": 40,
+            "channel_data": [
+                {"bias": {"amplitude": [.4, .04, -2e-3]}},
+                {"bias": {
+                    "amplitude": [.5],
+                    "silence": True,
+                }},
+                {"dds": {
+                    "amplitude": [.8, .08, -4e-3, 0],
+                    "phase": [.5, .05, .04/40],
+                    "clear": True,
+                }},
+            ],
+        },
+        {
+            "duration": 20,
+            "channel_data": [
+                {"bias": {"amplitude": [.4, -.04, 2e-3]}},
+                {"bias": {"amplitude": [.5, 0, -7.5e-3, 7.5e-4]}},
+                {"dds": {
+                    "amplitude": [.8, -.08, 4e-3, 0],
+                    "phase": [-.5],
+                }},
+            ],
+            "wait_trigger": True,
+            "jump": True,
+        },
+    ]
+]