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phaser: doc tweaks

This commit is contained in:
Robert Jördens 2020-09-12 19:59:49 +02:00
parent c3728678d6
commit b619f657b9
1 changed files with 23 additions and 16 deletions
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39
artiq/coredevice/phaser.py
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@ -76,8 +76,9 @@ class Phaser:
The four 16 bit 500 MS/s DAC data streams are sent via a 32 bit parallel The four 16 bit 500 MS/s DAC data streams are sent via a 32 bit parallel
LVDS bus operating at 1 Gb/s per pin pair and processed in the DAC. On the LVDS bus operating at 1 Gb/s per pin pair and processed in the DAC. On the
DAC 2x interpolation, sinx/x compensation, quadrature modulator compensation, DAC 2x interpolation, sinx/x compensation, quadrature modulator
fine and coarse mixing as well as group delay capabilities are available. compensation, fine and coarse mixing as well as group delay capabilities
are available.
The latency/group delay from the RTIO events setting The latency/group delay from the RTIO events setting
:class:`PhaserOscillator` or :class:`PhaserChannel` DUC parameters all they :class:`PhaserOscillator` or :class:`PhaserChannel` DUC parameters all they
@ -97,16 +98,19 @@ class Phaser:
31.5 dB range step attenuator and is available at the front panel. 31.5 dB range step attenuator and is available at the front panel.
The DAC, the analog quadrature upconverters and the two attenuators are The DAC, the analog quadrature upconverters and the two attenuators are
configured through a shared SPI bus that is accessed and controlled via FPGA configured through a shared SPI bus that is accessed and controlled via
registers. FPGA registers.
:param channel: Base RTIO channel number :param channel: Base RTIO channel number
:param core_device: Core device name (default: "core") :param core_device: Core device name (default: "core")
:param miso_delay: Fastlink MISO signal delay to account for cable :param miso_delay: Fastlink MISO signal delay to account for cable
and buffer round trip. This might be automated later. and buffer round trip. This might be automated later.
:attr:`channel`: List of two :class:`PhaserChannel` to access oscillators Attributes:
and digital upconverter.
* :attr:`channel`: List of two :class:`PhaserChannel`
To access oscillators, digital upconverters, PLL/VCO analog
quadrature upconverters and attenuators.
""" """
kernel_invariants = {"core", "channel_base", "t_frame", "miso_delay"} kernel_invariants = {"core", "channel_base", "t_frame", "miso_delay"}
@ -185,7 +189,7 @@ class Phaser:
def set_fan_mu(self, pwm): def set_fan_mu(self, pwm):
"""Set the fan duty cycle. """Set the fan duty cycle.
:param pwm: Duty cycle (8 bit) :param pwm: Duty cycle in machine units (8 bit)
""" """
self.write8(PHASER_ADDR_FAN, pwm) self.write8(PHASER_ADDR_FAN, pwm)
@ -228,13 +232,13 @@ class Phaser:
Bit flags are: Bit flags are:
* `PHASER_STA_DAC_ALARM`: DAC alarm pin * :const:`PHASER_STA_DAC_ALARM`: DAC alarm pin
* `PHASER_STA_TRF0_LD`: Quadrature upconverter 0 lock detect * :const:`PHASER_STA_TRF0_LD`: Quadrature upconverter 0 lock detect
* `PHASER_STA_TRF1_LD`: Quadrature upconverter 1 lock detect * :const:`PHASER_STA_TRF1_LD`: Quadrature upconverter 1 lock detect
* `PHASER_STA_TERM0`: ADC channel 0 termination indicator * :const:`PHASER_STA_TERM0`: ADC channel 0 termination indicator
* `PHASER_STA_TERM1`: ADC channel 1 termination indicator * :const:`PHASER_STA_TERM1`: ADC channel 1 termination indicator
* `PHASER_STA_SPI_IDLE`: SPI machine is idle and data registers can be * :const:`PHASER_STA_SPI_IDLE`: SPI machine is idle and data registers
read/written can be read/written
:return: Status register :return: Status register
""" """
@ -339,7 +343,9 @@ class Phaser:
class PhaserChannel: class PhaserChannel:
"""Phaser channel IQ pair. """Phaser channel IQ pair.
:attr:`oscillator`: List of five :class:`PhaserOscillator`. Attributes:
* :attr:`oscillator`: List of five :class:`PhaserOscillator`.
.. note:: The amplitude sum of the oscillators must be less than one to .. note:: The amplitude sum of the oscillators must be less than one to
avoid clipping or overflow. If any of the DDS or DUC frequencies are avoid clipping or overflow. If any of the DDS or DUC frequencies are
@ -433,7 +439,7 @@ class PhaserChannel:
def set_att_mu(self, data): def set_att_mu(self, data):
"""Set channel attenuation. """Set channel attenuation.
:param data: Attenuator data :param data: Attenuator data in machine units (8 bit)
""" """
div = 34 # 30 ns min period div = 34 # 30 ns min period
t_xfer = self.phaser.core.seconds_to_mu((8 + 1)*div*4*ns) t_xfer = self.phaser.core.seconds_to_mu((8 + 1)*div*4*ns)
@ -448,6 +454,7 @@ class PhaserChannel:
:param att: Attenuation in dB :param att: Attenuation in dB
""" """
# 2 lsb are inactive, resulting in 8 LSB per dB
data = 0xff - int32(round(att*8)) data = 0xff - int32(round(att*8))
if data < 0 or data > 0xff: if data < 0 or data > 0xff:
raise ValueError("invalid attenuation") raise ValueError("invalid attenuation")