from artiq.language.core import *
from artiq.language.types import *
from artiq.coredevice.rtio import rtio_output, rtio_input_data
from artiq.coredevice import spi2 as spi
from artiq.language.units import us
[docs]
@portable
def shuttler_volt_to_mu(volt):
"""Return the equivalent DAC code. Valid input range is from -10 to
10 - LSB.
"""
return round((1 << 16) * (volt / 20.0)) & 0xffff
[docs]
class Config:
"""Shuttler configuration registers interface.
The configuration registers control waveform phase auto-clear, and pre-DAC
gain & offset values for calibration with ADC on the Shuttler AFE card.
To find the calibrated DAC code, the Shuttler Core first multiplies the
output data with pre-DAC gain, then adds the offset.
.. note::
The DAC code is capped at 0x7fff and 0x8000.
:param channel: RTIO channel number of this interface.
:param core_device: Core device name.
"""
kernel_invariants = {
"core", "channel", "target_base", "target_read",
"target_gain", "target_offset", "target_clr"
}
def __init__(self, dmgr, channel, core_device="core"):
self.core = dmgr.get(core_device)
self.channel = channel
self.target_base = channel << 8
self.target_read = 1 << 6
self.target_gain = 0 * (1 << 4)
self.target_offset = 1 * (1 << 4)
self.target_clr = 1 * (1 << 5)
[docs]
@kernel
def set_clr(self, clr):
"""Set/Unset waveform phase clear bits.
Each bit corresponds to a Shuttler waveform generator core. Setting a
clear bit forces the Shuttler Core to clear the phase accumulator on
waveform trigger (See :class:`Trigger` for the trigger method).
Otherwise, the phase accumulator increments from its original value.
:param clr: Waveform phase clear bits. The MSB corresponds to Channel
15, LSB corresponds to Channel 0.
"""
rtio_output(self.target_base | self.target_clr, clr)
[docs]
@kernel
def set_gain(self, channel, gain):
"""Set the 16-bits pre-DAC gain register of a Shuttler Core channel.
The `gain` parameter represents the decimal portion of the gain
factor. The MSB represents 0.5 and the sign bit. Hence, the valid
total gain value (1 +/- 0.gain) ranges from 0.5 to 1.5 - LSB.
:param channel: Shuttler Core channel to be configured.
:param gain: Shuttler Core channel gain.
"""
rtio_output(self.target_base | self.target_gain | channel, gain)
[docs]
@kernel
def get_gain(self, channel):
"""Return the pre-DAC gain value of a Shuttler Core channel.
:param channel: The Shuttler Core channel.
:return: Pre-DAC gain value. See :meth:`set_gain`.
"""
rtio_output(self.target_base | self.target_gain |
self.target_read | channel, 0)
return rtio_input_data(self.channel)
[docs]
@kernel
def set_offset(self, channel, offset):
"""Set the 16-bits pre-DAC offset register of a Shuttler Core channel.
.. seealso::
:meth:`shuttler_volt_to_mu`
:param channel: Shuttler Core channel to be configured.
:param offset: Shuttler Core channel offset.
"""
rtio_output(self.target_base | self.target_offset | channel, offset)
[docs]
@kernel
def get_offset(self, channel):
"""Return the pre-DAC offset value of a Shuttler Core channel.
:param channel: The Shuttler Core channel.
:return: Pre-DAC offset value. See :meth:`set_offset`.
"""
rtio_output(self.target_base | self.target_offset |
self.target_read | channel, 0)
return rtio_input_data(self.channel)
[docs]
class DCBias:
"""Shuttler Core cubic DC-bias spline.
A Shuttler channel can generate a waveform `w(t)` that is the sum of a
cubic spline `a(t)` and a sinusoid modulated in amplitude by a cubic
spline `b(t)` and in phase/frequency by a quadratic spline `c(t)`, where
.. math::
w(t) = a(t) + b(t) * cos(c(t))
And `t` corresponds to time in seconds.
This class controls the cubic spline `a(t)`, in which
.. math::
a(t) = p_0 + p_1t + \\frac{p_2t^2}{2} + \\frac{p_3t^3}{6}
And `a(t)` is in Volt.
:param channel: RTIO channel number of this DC-bias spline interface.
:param core_device: Core device name.
"""
kernel_invariants = {"core", "channel", "target_o"}
def __init__(self, dmgr, channel, core_device="core"):
self.core = dmgr.get(core_device)
self.channel = channel
self.target_o = channel << 8
[docs]
class DDS:
"""Shuttler Core DDS spline.
A Shuttler channel can generate a waveform `w(t)` that is the sum of a
cubic spline `a(t)` and a sinusoid modulated in amplitude by a cubic
spline `b(t)` and in phase/frequency by a quadratic spline `c(t)`, where
.. math::
w(t) = a(t) + b(t) * cos(c(t))
And `t` corresponds to time in seconds.
This class controls the cubic spline `b(t)` and quadratic spline `c(t)`,
in which
.. math::
b(t) &= g * (q_0 + q_1t + \\frac{q_2t^2}{2} + \\frac{q_3t^3}{6})
c(t) &= r_0 + r_1t + \\frac{r_2t^2}{2}
And `b(t)` is in Volt, `c(t)` is in number of turns. Note that `b(t)`
contributes to a constant gain of :math:`g=1.64676`.
:param channel: RTIO channel number of this DC-bias spline interface.
:param core_device: Core device name.
"""
kernel_invariants = {"core", "channel", "target_o"}
def __init__(self, dmgr, channel, core_device="core"):
self.core = dmgr.get(core_device)
self.channel = channel
self.target_o = channel << 8
[docs]
class Trigger:
"""Shuttler Core spline coefficients update trigger.
:param channel: RTIO channel number of the trigger interface.
:param core_device: Core device name.
"""
kernel_invariants = {"core", "channel", "target_o"}
def __init__(self, dmgr, channel, core_device="core"):
self.core = dmgr.get(core_device)
self.channel = channel
self.target_o = channel << 8
[docs]
@kernel
def trigger(self, trig_out):
"""Triggers coefficient update of (a) Shuttler Core channel(s).
Each bit corresponds to a Shuttler waveform generator core. Setting
`trig_out` bits commits the pending coefficient update (from
`set_waveform` in :class:`DCBias` and :class:`DDS`) to the Shuttler Core
synchronously.
:param trig_out: Coefficient update trigger bits. The MSB corresponds
to Channel 15, LSB corresponds to Channel 0.
"""
rtio_output(self.target_o, trig_out)
RELAY_SPI_CONFIG = (0*spi.SPI_OFFLINE | 1*spi.SPI_END |
0*spi.SPI_INPUT | 0*spi.SPI_CS_POLARITY |
0*spi.SPI_CLK_POLARITY | 0*spi.SPI_CLK_PHASE |
0*spi.SPI_LSB_FIRST | 0*spi.SPI_HALF_DUPLEX)
ADC_SPI_CONFIG = (0*spi.SPI_OFFLINE | 0*spi.SPI_END |
0*spi.SPI_INPUT | 0*spi.SPI_CS_POLARITY |
1*spi.SPI_CLK_POLARITY | 1*spi.SPI_CLK_PHASE |
0*spi.SPI_LSB_FIRST | 0*spi.SPI_HALF_DUPLEX)
# SPI clock write and read dividers
# CS should assert at least 9.5 ns after clk pulse
SPIT_RELAY_WR = 4
# 25 ns high/low pulse hold (limiting for write)
SPIT_ADC_WR = 4
SPIT_ADC_RD = 16
# SPI CS line
CS_RELAY = 1 << 0
CS_LED = 1 << 1
CS_ADC = 1 << 0
# Referenced AD4115 registers
_AD4115_REG_STATUS = 0x00
_AD4115_REG_ADCMODE = 0x01
_AD4115_REG_DATA = 0x04
_AD4115_REG_ID = 0x07
_AD4115_REG_CH0 = 0x10
_AD4115_REG_SETUPCON0 = 0x20
[docs]
class Relay:
"""Shuttler AFE relay switches.
It controls the AFE relay switches and the LEDs. Switch on the relay to
enable AFE output; And off to disable the output. The LEDs indicates the
relay status.
.. note::
The relay does not disable ADC measurements. Voltage of any channels
can still be read by the ADC even after switching off the relays.
:param spi_device: SPI bus device name.
:param core_device: Core device name.
"""
kernel_invariant = {"core", "bus"}
def __init__(self, dmgr, spi_device, core_device="core"):
self.core = dmgr.get(core_device)
self.bus = dmgr.get(spi_device)
[docs]
@kernel
def init(self):
"""Initialize SPI device.
Configures the SPI bus to 16-bits, write-only, simultaneous relay
switches and LED control.
"""
self.bus.set_config_mu(
RELAY_SPI_CONFIG, 16, SPIT_RELAY_WR, CS_RELAY | CS_LED)
[docs]
@kernel
def enable(self, en: TInt32):
"""Enable/Disable relay switches of corresponding channels.
Each bit corresponds to the relay switch of a channel. Asserting a bit
turns on the corresponding relay switch; Deasserting the same bit
turns off the switch instead.
:param en: Switch enable bits. The MSB corresponds to Channel 15, LSB
corresponds to Channel 0.
"""
self.bus.write(en << 16)
[docs]
class ADC:
"""Shuttler AFE ADC (AD4115) driver.
:param spi_device: SPI bus device name.
:param core_device: Core device name.
"""
kernel_invariant = {"core", "bus"}
def __init__(self, dmgr, spi_device, core_device="core"):
self.core = dmgr.get(core_device)
self.bus = dmgr.get(spi_device)
[docs]
@kernel
def read_id(self) -> TInt32:
"""Read the product ID of the ADC.
The expected return value is 0x38DX, the 4 LSbs are don't cares.
:return: The read-back product ID.
"""
return self.read16(_AD4115_REG_ID)
[docs]
@kernel
def reset(self):
"""AD4115 reset procedure.
This performs a write operation of 96 serial clock cycles with DIN
held at high. It resets the entire device, including the register
contents.
.. note::
The datasheet only requires 64 cycles, but reasserting `CS_n` right
after the transfer appears to interrupt the start-up sequence.
"""
self.bus.set_config_mu(ADC_SPI_CONFIG, 32, SPIT_ADC_WR, CS_ADC)
self.bus.write(0xffffffff)
self.bus.write(0xffffffff)
self.bus.set_config_mu(
ADC_SPI_CONFIG | spi.SPI_END, 32, SPIT_ADC_WR, CS_ADC)
self.bus.write(0xffffffff)
[docs]
@kernel
def read8(self, addr: TInt32) -> TInt32:
"""Read from 8 bit register.
:param addr: Register address.
:return: Read-back register content.
"""
self.bus.set_config_mu(
ADC_SPI_CONFIG | spi.SPI_END | spi.SPI_INPUT,
16, SPIT_ADC_RD, CS_ADC)
self.bus.write((addr | 0x40) << 24)
return self.bus.read() & 0xff
[docs]
@kernel
def read16(self, addr: TInt32) -> TInt32:
"""Read from 16 bit register.
:param addr: Register address.
:return: Read-back register content.
"""
self.bus.set_config_mu(
ADC_SPI_CONFIG | spi.SPI_END | spi.SPI_INPUT,
24, SPIT_ADC_RD, CS_ADC)
self.bus.write((addr | 0x40) << 24)
return self.bus.read() & 0xffff
[docs]
@kernel
def read24(self, addr: TInt32) -> TInt32:
"""Read from 24 bit register.
:param addr: Register address.
:return: Read-back register content.
"""
self.bus.set_config_mu(
ADC_SPI_CONFIG | spi.SPI_END | spi.SPI_INPUT,
32, SPIT_ADC_RD, CS_ADC)
self.bus.write((addr | 0x40) << 24)
return self.bus.read() & 0xffffff
[docs]
@kernel
def write8(self, addr: TInt32, data: TInt32):
"""Write to 8 bit register.
:param addr: Register address.
:param data: Data to be written.
"""
self.bus.set_config_mu(
ADC_SPI_CONFIG | spi.SPI_END, 16, SPIT_ADC_WR, CS_ADC)
self.bus.write(addr << 24 | (data & 0xff) << 16)
[docs]
@kernel
def write16(self, addr: TInt32, data: TInt32):
"""Write to 16 bit register.
:param addr: Register address.
:param data: Data to be written.
"""
self.bus.set_config_mu(
ADC_SPI_CONFIG | spi.SPI_END, 24, SPIT_ADC_WR, CS_ADC)
self.bus.write(addr << 24 | (data & 0xffff) << 8)
[docs]
@kernel
def write24(self, addr: TInt32, data: TInt32):
"""Write to 24 bit register.
:param addr: Register address.
:param data: Data to be written.
"""
self.bus.set_config_mu(
ADC_SPI_CONFIG | spi.SPI_END, 32, SPIT_ADC_WR, CS_ADC)
self.bus.write(addr << 24 | (data & 0xffffff))
[docs]
@kernel
def read_ch(self, channel: TInt32) -> TFloat:
"""Sample a Shuttler channel on the AFE.
It performs a single conversion using profile 0 and setup 0, on the
selected channel. The sample is then recovered and converted to volt.
:param channel: Shuttler channel to be sampled.
:return: Voltage sample in volt.
"""
# Always configure Profile 0 for single conversion
self.write16(_AD4115_REG_CH0, 0x8000 | ((channel * 2 + 1) << 4))
self.write16(_AD4115_REG_SETUPCON0, 0x1300)
self.single_conversion()
delay(100*us)
adc_code = self.read24(_AD4115_REG_DATA)
return ((adc_code / (1 << 23)) - 1) * 2.5 / 0.1
[docs]
@kernel
def single_conversion(self):
"""Place the ADC in single conversion mode.
The ADC returns to standby mode after the conversion is complete.
"""
self.write16(_AD4115_REG_ADCMODE, 0x8010)
[docs]
@kernel
def standby(self):
"""Place the ADC in standby mode and disables power down the clock.
The ADC can be returned to single conversion mode by calling
:meth:`single_conversion`.
"""
# Selecting internal XO (0b00) also disables clock during standby
self.write16(_AD4115_REG_ADCMODE, 0x8020)
[docs]
@kernel
def power_down(self):
"""Place the ADC in power-down mode.
The ADC must be reset before returning to other modes.
.. note::
The AD4115 datasheet suggests placing the ADC in standby mode
before power-down. This is to prevent accidental entry into the
power-down mode.
.. seealso::
:meth:`standby`
:meth:`power_up`
"""
self.write16(_AD4115_REG_ADCMODE, 0x8030)
[docs]
@kernel
def power_up(self):
"""Exit the ADC power-down mode.
The ADC should be in power-down mode before calling this method.
.. seealso::
:meth:`power_down`
"""
self.reset()
# Although the datasheet claims 500 us reset wait time, only waiting
# for ~500 us can result in DOUT pin stuck in high
delay(2500*us)
[docs]
@kernel
def calibrate(self, volts, trigger, config, samples=[-5.0, 0.0, 5.0]):
"""Calibrate the Shuttler waveform generator using the ADC on the AFE.
It finds the average slope rate and average offset by samples, and
compensate by writing the pre-DAC gain and offset registers in the
configuration registers.
.. note::
If the pre-calibration slope rate < 1, the calibration procedure
will introduce a pre-DAC gain compensation. However, this may
saturate the pre-DAC voltage code. (See :class:`Config` notes).
Shuttler cannot cover the entire +/- 10 V range in this case.
.. seealso::
:meth:`Config.set_gain`
:meth:`Config.set_offset`
:param volts: A list of all 16 cubic DC-bias spline.
(See :class:`DCBias`)
:param trigger: The Shuttler spline coefficient update trigger.
:param config: The Shuttler Core configuration registers.
:param samples: A list of sample voltages for calibration. There must
be at least 2 samples to perform slope rate calculation.
"""
assert len(volts) == 16
assert len(samples) > 1
measurements = [0.0] * len(samples)
for ch in range(16):
# Find the average slope rate and offset
for i in range(len(samples)):
self.core.break_realtime()
volts[ch].set_waveform(
shuttler_volt_to_mu(samples[i]), 0, 0, 0)
trigger.trigger(1 << ch)
measurements[i] = self.read_ch(ch)
# Find the average output slope
slope_sum = 0.0
for i in range(len(samples) - 1):
slope_sum += (measurements[i+1] - measurements[i])/(samples[i+1] - samples[i])
slope_avg = slope_sum / (len(samples) - 1)
gain_code = int32(1 / slope_avg * (2 ** 16)) & 0xffff
# Scale the measurements by 1/slope, find average offset
offset_sum = 0.0
for i in range(len(samples)):
offset_sum += (measurements[i] / slope_avg) - samples[i]
offset_avg = offset_sum / len(samples)
offset_code = shuttler_volt_to_mu(-offset_avg)
self.core.break_realtime()
config.set_gain(ch, gain_code)
delay_mu(int64(self.core.ref_multiplier))
config.set_offset(ch, offset_code)