M-Labs
/
artiq
mirror of https://github.com/m-labs/artiq.git
2
0
Fork 1
Code Issues Projects Releases Wiki Activity
artiq/artiq/coredevice/ad9910.py

520 lines
20 KiB
Python
Raw Blame History

from numpy import int32, int64
from artiq.language.core import (
kernel, delay, portable, delay_mu, now_mu, at_mu)
from artiq.language.units import us, ns, ms
from artiq.coredevice import spi2 as spi
from artiq.coredevice import urukul
# Work around ARTIQ-Python import machinery
urukul_sta_pll_lock = urukul.urukul_sta_pll_lock
urukul_sta_smp_err = urukul.urukul_sta_smp_err
__all__ = [
"AD9910",
"PHASE_MODE_CONTINUOUS", "PHASE_MODE_ABSOLUTE", "PHASE_MODE_TRACKING"
]
_PHASE_MODE_DEFAULT = -1
PHASE_MODE_CONTINUOUS = 0
PHASE_MODE_ABSOLUTE = 1
PHASE_MODE_TRACKING = 2
_AD9910_REG_CFR1 = 0x00
_AD9910_REG_CFR2 = 0x01
_AD9910_REG_CFR3 = 0x02
_AD9910_REG_AUX_DAC = 0x03
_AD9910_REG_IO_UPD = 0x04
_AD9910_REG_FTW = 0x07
_AD9910_REG_POW = 0x08
_AD9910_REG_ASF = 0x09
_AD9910_REG_MSYNC = 0x0A
_AD9910_REG_DRAMPL = 0x0B
_AD9910_REG_DRAMPS = 0x0C
_AD9910_REG_DRAMPR = 0x0D
_AD9910_REG_PR0 = 0x0E
_AD9910_REG_PR1 = 0x0F
_AD9910_REG_PR2 = 0x10
_AD9910_REG_PR3 = 0x11
_AD9910_REG_PR4 = 0x12
_AD9910_REG_PR5 = 0x13
_AD9910_REG_PR6 = 0x14
_AD9910_REG_PR7 = 0x15
_AD9910_REG_RAM = 0x16
class AD9910:
"""
AD9910 DDS channel on Urukul.
This class supports a single DDS channel and exposes the DDS,
the digital step attenuator, and the RF switch.
:param chip_select: Chip select configuration. On Urukul this is an
encoded chip select and not "one-hot": 3 to address multiple chips
(as configured through CFG_MASK_NU), 4-7 for individual channels.
:param cpld_device: Name of the Urukul CPLD this device is on.
:param sw_device: Name of the RF switch device. The RF switch is a
TTLOut channel available as the :attr:`sw` attribute of this instance.
:param pll_n: DDS PLL multiplier. The DDS sample clock is
f_ref/4*pll_n where f_ref is the reference frequency (set in the parent
Urukul CPLD instance).
:param pll_cp: DDS PLL charge pump setting.
:param pll_vco: DDS PLL VCO range selection.
:param sync_delay_seed: SYNC_IN delay tuning starting value.
To stabilize the SYNC_IN delay tuning, run :meth:`tune_sync_delay` once
and set this to the delay tap number returned (default: -1 to signal no
synchronization and no tuning during :meth:`init`).
:param io_update_delay: IO_UPDATE pulse alignment delay.
To align IO_UPDATE to SYNC_CLK, run :meth:`tune_io_update_delay` and
set this to the delay tap number returned.
"""
kernel_invariants = {"chip_select", "cpld", "core", "bus",
"ftw_per_hz", "pll_n", "io_update_delay", "sysclk_per_mu"}
def __init__(self, dmgr, chip_select, cpld_device, sw_device=None,
pll_n=40, pll_cp=7, pll_vco=5, sync_delay_seed=-1,
io_update_delay=0):
self.cpld = dmgr.get(cpld_device)
self.core = self.cpld.core
self.bus = self.cpld.bus
assert 3 <= chip_select <= 7
self.chip_select = chip_select
if sw_device:
self.sw = dmgr.get(sw_device)
self.kernel_invariants.add("sw")
assert 12 <= pll_n <= 127
self.pll_n = pll_n
assert self.cpld.refclk/4 <= 60e6
sysclk = self.cpld.refclk*pll_n/4 # Urukul clock fanout divider
assert sysclk <= 1e9
self.ftw_per_hz = (1 << 32)/sysclk
self.sysclk_per_mu = int(round(sysclk*self.core.ref_period))
assert self.sysclk_per_mu == sysclk*self.core.ref_period
assert 0 <= pll_vco <= 5
vco_min, vco_max = [(370, 510), (420, 590), (500, 700),
(600, 880), (700, 950), (820, 1150)][pll_vco]
assert vco_min <= sysclk/1e6 <= vco_max
self.pll_vco = pll_vco
assert 0 <= pll_cp <= 7
self.pll_cp = pll_cp
self.sync_delay_seed = sync_delay_seed
self.io_update_delay = io_update_delay
self.phase_mode = PHASE_MODE_CONTINUOUS
@kernel
def set_phase_mode(self, phase_mode):
"""Sets the default phase mode for future calls to :meth:`set` and
:meth:`set_mu`. Supported phase modes are:
* :const:`PHASE_MODE_CONTINUOUS`: the phase accumulator is unchanged
when changing frequency or phase. The DDS phase is the sum of the
phase accumulator and the phase offset. The only discontinuous
changes in the DDS output phase come from changes to the phase
offset. This mode is also knows as "relative phase mode".
:math:`\phi(t) = q(t^\prime) + p + (t - t^\prime) f`
* :const:`PHASE_MODE_ABSOLUTE`: the phase accumulator is reset when
changing frequency or phase. Thus, the phase of the DDS at the
time of the change is equal to the specified phase offset.
:math:`\phi(t) = p + (t - t^\prime) f`
* :const:`PHASE_MODE_TRACKING`: when changing frequency or phase,
the phase accumulator is cleared and the phase offset is offset
by the value the phase accumulator would have if the DDS had been
running at the specified frequency since a given fiducial
time stamp. This is functionally equivalent to
:const:`PHASE_MODE_ABSOLUTE`. The only difference is the fiducial
time stamp. This mode is also known as "coherent phase mode".
The default fiducial time stamp is 0.
:math:`\phi(t) = p + (t - T) f`
Where:
* :math:`\phi(t)`: the DDS output phase
* :math:`q(t) = \phi(t) - p`: DDS internal phase accumulator
* :math:`p`: phase offset
* :math:`f`: frequency
* :math:`t^\prime`: time stamp of setting :math:`p`, :math:`f`
* :math:`T`: fiducial time stamp
* :math:`t`: running time
.. warning:: This setting may become inconsistent when used as part of
a DMA recording. When using DMA, it is recommended to specify the
phase mode explicitly when calling :meth:`set` or :meth:`set_mu`.
"""
self.phase_mode = phase_mode
@kernel
def write32(self, addr, data):
"""Write to 32 bit register.
:param addr: Register address
:param data: Data to be written
"""
self.bus.set_config_mu(urukul.SPI_CONFIG, 8,
urukul.SPIT_DDS_WR, self.chip_select)
self.bus.write(addr << 24)
self.bus.set_config_mu(urukul.SPI_CONFIG | spi.SPI_END, 32,
urukul.SPIT_DDS_WR, self.chip_select)
self.bus.write(data)
@kernel
def read32(self, addr):
"""Read from 32 bit register.
:param addr: Register address
"""
self.bus.set_config_mu(urukul.SPI_CONFIG, 8,
urukul.SPIT_DDS_WR, self.chip_select)
self.bus.write((addr | 0x80) << 24)
self.bus.set_config_mu(urukul.SPI_CONFIG | spi.SPI_END
| spi.SPI_INPUT, 32,
urukul.SPIT_DDS_RD, self.chip_select)
self.bus.write(0)
return self.bus.read()
@kernel
def write64(self, addr, data_high, data_low):
"""Write to 64 bit register.
:param addr: Register address
:param data_high: High (MSB) 32 bits of the data
:param data_low: Low (LSB) 32 data bits
"""
self.bus.set_config_mu(urukul.SPI_CONFIG, 8,
urukul.SPIT_DDS_WR, self.chip_select)
self.bus.write(addr << 24)
self.bus.set_config_mu(urukul.SPI_CONFIG, 32,
urukul.SPIT_DDS_WR, self.chip_select)
self.bus.write(data_high)
self.bus.set_config_mu(urukul.SPI_CONFIG | spi.SPI_END, 32,
urukul.SPIT_DDS_WR, self.chip_select)
self.bus.write(data_low)
@kernel
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(1*us)
delay(1*ms)
if not blind:
# Use the AUX DAC setting to identify and confirm presence
aux_dac = self.read32(_AD9910_REG_AUX_DAC)
if aux_dac & 0xff != 0x7f:
raise ValueError("Urukul AD9910 AUX_DAC mismatch")
delay(50*us) # slack
# Configure PLL settings and bring up PLL
# enable amplitude scale from profiles
# read effective FTW
# sync timing validation disable (enabled later)
self.write32(_AD9910_REG_CFR2, 0x01010020)
self.cpld.io_update.pulse(1*us)
cfr3 = (0x0807c100 | (self.pll_vco << 24) |
(self.pll_cp << 19) | (self.pll_n << 1))
self.write32(_AD9910_REG_CFR3, cfr3 | 0x400) # PFD reset
self.cpld.io_update.pulse(1*us)
self.write32(_AD9910_REG_CFR3, cfr3)
self.cpld.io_update.pulse(1*us)
if blind:
delay(100*ms)
else:
# Wait for PLL lock, up to 100 ms
for i in range(100):
sta = self.cpld.sta_read()
lock = urukul_sta_pll_lock(sta)
delay(1*ms)
if lock & (1 << self.chip_select - 4):
break
if i >= 100 - 1:
raise ValueError("PLL lock timeout")
if self.sync_delay_seed >= 0:
self.tune_sync_delay(self.sync_delay_seed)
delay(1*ms)
@kernel
def power_down(self, bits=0b1111):
"""Power down DDS.
:param bits: power down bits, see datasheet
"""
self.write32(_AD9910_REG_CFR1, 0x00000002 | (bits << 4))
self.cpld.io_update.pulse(1*us)
@kernel
def set_mu(self, ftw, pow=0, asf=0x3fff, phase_mode=_PHASE_MODE_DEFAULT,
ref_time=-1):
"""Set profile 0 data in machine units.
This uses machine units (FTW, POW, ASF). The frequency tuning word
width is 32, the phase offset word width is 16, and the amplitude
scale factor width is 12.
After the SPI transfer, the shared IO update pin is pulsed to
activate the data.
.. seealso: :meth:`set_phase_mode` for a definition of the different
phase modes.
:param ftw: Frequency tuning word: 32 bit.
:param pow: Phase tuning word: 16 bit unsigned.
:param asf: Amplitude scale factor: 14 bit unsigned.
:param phase_mode: If specified, overrides the default phase mode set
by :meth:`set_phase_mode` for this call.
:param ref_time: Fiducial time used to compute absolute or tracking
phase updates. In machine units as obtained by `now_mu()`.
:return: Resulting phase offset word after application of phase
tracking offset. When using :const:`PHASE_MODE_CONTINUOUS` in
subsequent calls, use this value as the "current" phase.
"""
if phase_mode == _PHASE_MODE_DEFAULT:
phase_mode = self.phase_mode
# Align to coarse RTIO which aligns SYNC_CLK
at_mu(now_mu() & ~0xf)
if phase_mode != PHASE_MODE_CONTINUOUS:
# Auto-clear phase accumulator on IO_UPDATE.
# This is active already for the next IO_UPDATE
self.write32(_AD9910_REG_CFR1, 0x00002002)
if phase_mode == PHASE_MODE_TRACKING and ref_time < 0:
# set default fiducial time stamp
ref_time = 0
if ref_time >= 0:
# 32 LSB are sufficient.
# Also no need to use IO_UPDATE time as this
# is equivalent to an output pipeline latency.
dt = int32(now_mu()) - int32(ref_time)
pow += dt*ftw*self.sysclk_per_mu >> 16
self.write64(_AD9910_REG_PR0, (asf << 16) | pow, ftw)
delay_mu(int64(self.io_update_delay))
self.cpld.io_update.pulse_mu(8) # assumes 8 mu > t_SYSCLK
at_mu(now_mu() & ~0xf)
if phase_mode != PHASE_MODE_CONTINUOUS:
self.write32(_AD9910_REG_CFR1, 0x00000002)
# future IO_UPDATE will activate
return pow
@portable(flags={"fast-math"})
def frequency_to_ftw(self, frequency):
"""Returns the frequency tuning word corresponding to the given
frequency.
"""
return int32(round(self.ftw_per_hz*frequency))
@portable(flags={"fast-math"})
def turns_to_pow(self, turns):
"""Returns the phase offset word corresponding to the given phase
in turns."""
return int32(round(turns*0x10000))
@portable(flags={"fast-math"})
def amplitude_to_asf(self, amplitude):
"""Returns amplitude scale factor corresponding to given amplitude."""
return int32(round(amplitude*0x3ffe))
@portable(flags={"fast-math"})
def pow_to_turns(self, pow):
"""Returns the phase in turns corresponding to a given phase offset
word."""
return pow/0x10000
@kernel
def set(self, frequency, phase=0.0, amplitude=1.0,
phase_mode=_PHASE_MODE_DEFAULT, ref_time=-1):
"""Set profile 0 data in SI units.
.. seealso:: :meth:`set_mu`
:param ftw: Frequency in Hz
:param pow: Phase tuning word in turns
:param asf: Amplitude in units of full scale
:param phase_mode: Phase mode constant
:param ref_time: Fiducial time stamp in machine units
:return: Resulting phase offset in turns
"""
return self.pow_to_turns(self.set_mu(
self.frequency_to_ftw(frequency), self.turns_to_pow(phase),
self.amplitude_to_asf(amplitude), phase_mode, ref_time))
@kernel
def set_att_mu(self, att):
"""Set digital step attenuator in machine units.
.. seealso:: :meth:`artiq.coredevice.urukul.CPLD.set_att_mu`
:param att: Attenuation setting, 8 bit digital.
"""
self.cpld.set_att_mu(self.chip_select - 4, att)
@kernel
def set_att(self, att):
"""Set digital step attenuator in SI units.
.. seealso:: :meth:`artiq.coredevice.urukul.CPLD.set_att`
:param att: Attenuation in dB.
"""
self.cpld.set_att(self.chip_select - 4, att)
@kernel
def cfg_sw(self, state):
"""Set CPLD CFG RF switch state. The RF switch is controlled by the
logical or of the CPLD configuration shift register
RF switch bit and the SW TTL line (if used).
:param state: CPLD CFG RF switch bit
"""
self.cpld.cfg_sw(self.chip_select - 4, state)
@kernel
def set_sync(self, in_delay, window):
"""Set the relevant parameters in the multi device synchronization
register. See the AD9910 datasheet for details. The SYNC clock
generator preset value is set to zero, and the SYNC_OUT generator is
disabled.
:param in_delay: SYNC_IN delay tap (0-31) in steps of ~75ps
:param window: Symmetric SYNC_IN validation window (0-15) in
steps of ~75ps for both hold and setup margin.
"""
self.write32(_AD9910_REG_MSYNC,
(window << 28) | # SYNC S/H validation delay
(1 << 27) | # SYNC receiver enable
(0 << 26) | # SYNC generator disable
(0 << 25) | # SYNC generator SYS rising edge
(0 << 18) | # SYNC preset
(0 << 11) | # SYNC output delay
(in_delay << 3)) # SYNC receiver delay
@kernel
def clear_smp_err(self):
"""Clears the SMP_ERR flag and enables SMP_ERR validity monitoring.
Violations of the SYNC_IN sample and hold margins will result in
SMP_ERR being asserted. This then also activates the red LED on
the respective Urukul channel.
Also modifies CFR2.
"""
self.write32(_AD9910_REG_CFR2, 0x01010020) # clear SMP_ERR
self.cpld.io_update.pulse(1*us)
self.write32(_AD9910_REG_CFR2, 0x01010000) # enable SMP_ERR
self.cpld.io_update.pulse(1*us)
@kernel
def tune_sync_delay(self, sync_delay_seed):
"""Find a stable SYNC_IN delay.
This method first locates the smallest SYNC_IN validity window at
minimum window size and then increases the window a bit to provide some
slack and stability.
It starts scanning delays around `sync_delay_seed` (see the
device database arguments and :class:`AD9910`) at maximum validation
window size and decreases the window size until a valid delay is found.
:param sync_delay_seed: Start value for valid SYNC_IN delay search.
:return: Tuple of optimal delay and window size.
"""
dt = 14 # 1/(f_SYSCLK*75ps) taps per SYSCLK period
max_delay = dt # 14*75ps > 1ns
max_window = dt//4 + 1 # 2*75ps*4 = 600ps high > 1ns/2
min_window = max(0, max_window - 2) # 2*75ps hold, 2*75ps setup
for window in range(max_window - min_window + 1):
window = max_window - window
for in_delay in range(max_delay):
# alternate search direction around seed_delay
if in_delay & 1:
in_delay = -in_delay
in_delay = sync_delay_seed + (in_delay >> 1)
if in_delay < 0:
in_delay = 0
elif in_delay > 31:
in_delay = 31
self.set_sync(in_delay, window)
self.clear_smp_err()
# integrate SMP_ERR statistics for a few hundred cycles
delay(10*us)
err = urukul_sta_smp_err(self.cpld.sta_read())
err = (err >> (self.chip_select - 4)) & 1
delay(40*us) # slack
if not err:
window -= min_window # add margin
self.set_sync(in_delay, window)
self.clear_smp_err()
delay(40*us) # slack
return in_delay, window
raise ValueError("no valid window/delay")
@kernel
def measure_io_update_alignment(self, io_up_delay):
"""Use the digital ramp generator to locate the alignment between
IO_UPDATE and SYNC_CLK.
The ramp generator is set up to a linear frequency ramp
(dFTW/t_SYNC_CLK=1) and started at a RTIO time stamp.
After scanning the alignment, an IO_UPDATE delay midway between two
edges should be chosen.
:return: odd/even SYNC_CLK cycle indicator
"""
# set up DRG
# DRG ACC autoclear and LRR on io update
self.write32(_AD9910_REG_CFR1, 0x0000c002)
# DRG -> FTW, DRG enable
self.write32(_AD9910_REG_CFR2, 0x01090000)
# no limits
self.write64(_AD9910_REG_DRAMPL, -1, 0)
# DRCTL=0, dt=1 t_SYNC_CLK
self.write32(_AD9910_REG_DRAMPR, 0x00010000)
# dFTW = 1, (work around negative slope)
self.write64(_AD9910_REG_DRAMPS, -1, 0)
at_mu(now_mu() + 0x10 & ~0xf) # align to RTIO/2
self.cpld.io_update.pulse_mu(8)
# disable DRG autoclear and LRR on io_update
self.write32(_AD9910_REG_CFR1, 0x00000002)
# stop DRG
self.write64(_AD9910_REG_DRAMPS, 0, 0)
at_mu((now_mu() + 0x10 & ~0xf) + io_up_delay) # delay
self.cpld.io_update.pulse_mu(32 - io_up_delay) # realign
ftw = self.read32(_AD9910_REG_FTW) # read out effective FTW
delay(100*us) # slack
# disable DRG
self.write32(_AD9910_REG_CFR2, 0x01010000)
self.cpld.io_update.pulse_mu(8)
return ftw & 1
@kernel
def tune_io_update_delay(self):
"""Find a stable IO_UPDATE delay alignment.
Scan through increasing IO_UPDATE delays until a delay is found that
lets IO_UPDATE be registered in the next SYNC_CLK cycle. Return a
IO_UPDATE delay that is midway between two such SYNC_CLK transitions.
This method assumes that the IO_UPDATE TTLOut device has one machine
unit resolution (SERDES) and that the ratio between fine RTIO frequency
(RTIO time machine units) and SYNC_CLK is 4.
:return: Stable IO_UPDATE delay to be passed to the constructor
:class:`AD9910` via the device database.
"""
period = 4 # f_RTIO/f_SYNC = 4
max_delay = 8 # mu, 1 ns
d0 = self.io_update_delay
t0 = int32(self.measure_io_update_alignment(d0))
for i in range(max_delay - 1):
t = self.measure_io_update_alignment((d0 + i + 1) & (max_delay - 1))
if t != t0:
return (d0 + i + period//2) & (period - 1)
raise ValueError("no IO_UPDATE-SYNC_CLK alignment edge found")
Reference in New Issue View Git Blame Copy Permalink