Source code for artiq.coredevice.phaser

from numpy import int32, int64

from artiq.language.core import kernel, delay_mu, delay
from artiq.coredevice.rtio import rtio_output, rtio_input_data
from artiq.language.units import us, ns, ms, MHz
from artiq.language.types import TInt32
from artiq.coredevice.dac34h84 import DAC34H84
from artiq.coredevice.trf372017 import TRF372017


PHASER_BOARD_ID = 19
PHASER_ADDR_BOARD_ID = 0x00
PHASER_ADDR_HW_REV = 0x01
PHASER_ADDR_GW_REV = 0x02
PHASER_ADDR_CFG = 0x03
PHASER_ADDR_STA = 0x04
PHASER_ADDR_CRC_ERR = 0x05
PHASER_ADDR_LED = 0x06
PHASER_ADDR_FAN = 0x07
PHASER_ADDR_DUC_STB = 0x08
PHASER_ADDR_ADC_CFG = 0x09
PHASER_ADDR_SPI_CFG = 0x0a
PHASER_ADDR_SPI_DIVLEN = 0x0b
PHASER_ADDR_SPI_SEL = 0x0c
PHASER_ADDR_SPI_DATW = 0x0d
PHASER_ADDR_SPI_DATR = 0x0e
PHASER_ADDR_SYNC_DLY = 0x0f

PHASER_ADDR_DUC0_CFG = 0x10
# PHASER_ADDR_DUC0_RESERVED0 = 0x11
PHASER_ADDR_DUC0_F = 0x12
PHASER_ADDR_DUC0_P = 0x16
PHASER_ADDR_DAC0_DATA = 0x18
PHASER_ADDR_DAC0_TEST = 0x1c

PHASER_ADDR_DUC1_CFG = 0x20
# PHASER_ADDR_DUC1_RESERVED0 = 0x21
PHASER_ADDR_DUC1_F = 0x22
PHASER_ADDR_DUC1_P = 0x26
PHASER_ADDR_DAC1_DATA = 0x28
PHASER_ADDR_DAC1_TEST = 0x2c

PHASER_SEL_DAC = 1 << 0
PHASER_SEL_TRF0 = 1 << 1
PHASER_SEL_TRF1 = 1 << 2
PHASER_SEL_ATT0 = 1 << 3
PHASER_SEL_ATT1 = 1 << 4

PHASER_STA_DAC_ALARM = 1 << 0
PHASER_STA_TRF0_LD = 1 << 1
PHASER_STA_TRF1_LD = 1 << 2
PHASER_STA_TERM0 = 1 << 3
PHASER_STA_TERM1 = 1 << 4
PHASER_STA_SPI_IDLE = 1 << 5

PHASER_DAC_SEL_DUC = 0
PHASER_DAC_SEL_TEST = 1

PHASER_HW_REV_VARIANT = 1 << 4


[docs]class Phaser: """Phaser 4-channel, 16-bit, 1 GS/s DAC coredevice driver. Phaser contains a 4 channel, 1 GS/s DAC chip with integrated upconversion, quadrature modulation compensation and interpolation features. The coredevice produces 2 IQ (in-phase and quadrature) data streams with 25 MS/s and 14 bit per quadrature. Each data stream supports 5 independent numerically controlled IQ oscillators (NCOs, DDSs with 32 bit frequency, 16 bit phase, 15 bit amplitude, and phase accumulator clear functionality) added together. See :class:`PhaserChannel` and :class:`PhaserOscillator`. Together with a data clock, framing marker, a checksum and metadata for register access the streams are sent in groups of 8 samples over 1.5 Gb/s FastLink via a single EEM connector from coredevice to Phaser. On Phaser in the FPGA the data streams are buffered and interpolated from 25 MS/s to 500 MS/s 16 bit followed by a 500 MS/s digital upconverter with adjustable frequency and phase. The interpolation passband is 20 MHz wide, passband ripple is less than 1e-3 amplitude, stopband attenuation is better than 75 dB at offsets > 15 MHz and better than 90 dB at offsets > 30 MHz. 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 (Texas Instruments DAC34H84). On the DAC 2x interpolation, sinx/x compensation, quadrature modulator compensation, fine and coarse mixing as well as group delay capabilities are available. If desired, these features my be configured via the `dac` dictionary. The latency/group delay from the RTIO events setting :class:`PhaserOscillator` or :class:`PhaserChannel` DUC parameters all the way to the DAC outputs is deterministic. This enables deterministic absolute phase with respect to other RTIO input and output events. The four analog DAC outputs are passed through anti-aliasing filters. In the baseband variant, the even/in-phase DAC channels feed 31.5 dB range attenuators and are available on the front panel. The odd outputs are available at MMCX connectors on board. In the upconverter variant, each IQ output pair feeds one quadrature upconverter (Texas Instruments TRF372017) with integrated PLL/VCO. This digitally configured analog quadrature upconverter supports offset tuning for carrier and sideband suppression. The output from the upconverter passes through the 31.5 dB range step attenuator and is available at the front panel. The DAC, the analog quadrature upconverters and the attenuators are configured through a shared SPI bus that is accessed and controlled via FPGA registers. .. note:: Various register settings of the DAC and the quadrature upconverters are available to be modified through the `dac`, `trf0`, `trf1` dictionaries. These can be set through the device database (`device_db.py`). The settings are frozen during instantiation of the class and applied during `init()`. See the :class:`DAC34H84` and :class:`TRF372017` source for details. .. note:: To establish deterministic latency between RTIO time base and DAC output, the DAC FIFO read pointer value (`fifo_offset`) must be fixed. If `tune_fifo_offset=True` (the default) a value with maximum margin is determined automatically by `dac_tune_fifo_offset` each time `init()` is called. This value should be used for the `fifo_offset` key of the `dac` settings of Phaser in `device_db.py` and automatic tuning should be disabled by `tune_fifo_offset=False`. :param channel: Base RTIO channel number :param core_device: Core device name (default: "core") :param miso_delay: Fastlink MISO signal delay to account for cable and buffer round trip. Tuning this might be automated later. :param tune_fifo_offset: Tune the DAC FIFO read pointer offset (default=True) :param clk_sel: Select the external SMA clock input (1 or 0) :param sync_dly: SYNC delay with respect to ISTR. :param dac: DAC34H84 DAC settings as a dictionary. :param trf0: Channel 0 TRF372017 quadrature upconverter settings as a dictionary. :param trf1: Channel 1 TRF372017 quadrature upconverter settings as a dictionary. Attributes: * :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", "dac_mmap"} def __init__(self, dmgr, channel_base, miso_delay=1, tune_fifo_offset=True, clk_sel=0, sync_dly=0, dac=None, trf0=None, trf1=None, core_device="core"): self.channel_base = channel_base self.core = dmgr.get(core_device) # TODO: auto-align miso-delay in phy self.miso_delay = miso_delay # frame duration in mu (10 words, 8 clock cycles each 4 ns) # self.core.seconds_to_mu(10*8*4*ns) # unfortunately this returns 319 assert self.core.ref_period == 1*ns self.t_frame = 10*8*4 self.clk_sel = clk_sel self.tune_fifo_offset = tune_fifo_offset self.sync_dly = sync_dly self.dac_mmap = DAC34H84(dac).get_mmap() self.channel = [PhaserChannel(self, ch, trf) for ch, trf in enumerate([trf0, trf1])]
[docs] @kernel def init(self, debug=False): """Initialize the board. Verifies board and chip presence, resets components, performs communication and configuration tests and establishes initial conditions. """ board_id = self.read8(PHASER_ADDR_BOARD_ID) if board_id != PHASER_BOARD_ID: raise ValueError("invalid board id") delay(.1*ms) # slack hw_rev = self.read8(PHASER_ADDR_HW_REV) delay(.1*ms) # slack is_baseband = hw_rev & PHASER_HW_REV_VARIANT gw_rev = self.read8(PHASER_ADDR_GW_REV) if debug: print(gw_rev) self.core.break_realtime() delay(.1*ms) # slack # allow a few errors during startup and alignment since boot if self.get_crc_err() > 20: raise ValueError("large number of frame CRC errors") delay(.1*ms) # slack # reset self.set_cfg(dac_resetb=0, dac_sleep=1, dac_txena=0, trf0_ps=1, trf1_ps=1, att0_rstn=0, att1_rstn=0) self.set_leds(0x00) self.set_fan_mu(0) # bring dac out of reset, keep tx off self.set_cfg(clk_sel=self.clk_sel, dac_txena=0, trf0_ps=1, trf1_ps=1, att0_rstn=0, att1_rstn=0) delay(.1*ms) # slack # crossing dac_clk (reference) edges with sync_dly # changes the optimal fifo_offset by 4 self.set_sync_dly(self.sync_dly) # 4 wire SPI, sif4_enable self.dac_write(0x02, 0x0080) if self.dac_read(0x7f) != 0x5409: raise ValueError("DAC version readback invalid") delay(.1*ms) if self.dac_read(0x00) != 0x049c: raise ValueError("DAC config0 reset readback invalid") delay(.1*ms) t = self.get_dac_temperature() delay(.1*ms) if t < 10 or t > 90: raise ValueError("DAC temperature out of bounds") for data in self.dac_mmap: self.dac_write(data >> 16, data) delay(40*us) self.dac_sync() delay(40*us) # pll_ndivsync_ena disable config18 = self.dac_read(0x18) delay(.1*ms) self.dac_write(0x18, config18 & ~0x0800) patterns = [ [0xf05a, 0x05af, 0x5af0, 0xaf05], # test channel/iq/byte/nibble [0x7a7a, 0xb6b6, 0xeaea, 0x4545], # datasheet pattern a [0x1a1a, 0x1616, 0xaaaa, 0xc6c6], # datasheet pattern b ] # A data delay of 2*50 ps heuristically and reproducibly matches # FPGA+board+DAC skews. There is plenty of margin (>= 250 ps # either side) and no need to tune at runtime. # Parity provides another level of safety. for i in range(len(patterns)): delay(.5*ms) errors = self.dac_iotest(patterns[i]) if errors: raise ValueError("DAC iotest failure") delay(2*ms) # let it settle lvolt = self.dac_read(0x18) & 7 delay(.1*ms) if lvolt < 2 or lvolt > 5: raise ValueError("DAC PLL lock failed, check clocking") if self.tune_fifo_offset: fifo_offset = self.dac_tune_fifo_offset() if debug: print(fifo_offset) self.core.break_realtime() # self.dac_write(0x20, 0x0000) # stop fifo sync # alarm = self.get_sta() & 1 # delay(.1*ms) self.clear_dac_alarms() delay(2*ms) # let it run a bit alarms = self.get_dac_alarms() delay(.1*ms) # slack if alarms & ~0x0040: # ignore PLL alarms (see DS) if debug: print(alarms) self.core.break_realtime() # ignore alarms else: raise ValueError("DAC alarm") # avoid malformed output for: mixer_ena=1, nco_ena=0 after power up self.dac_write(self.dac_mmap[2] >> 16, self.dac_mmap[2] | (1 << 4)) delay(40*us) self.dac_sync() delay(100*us) self.dac_write(self.dac_mmap[2] >> 16, self.dac_mmap[2]) delay(40*us) self.dac_sync() delay(100*us) # power up trfs, release att reset self.set_cfg(clk_sel=self.clk_sel, dac_txena=0) for ch in range(2): channel = self.channel[ch] # test attenuator write and readback channel.set_att_mu(0x5a) if channel.get_att_mu() != 0x5a: raise ValueError("attenuator test failed") delay(.1*ms) channel.set_att_mu(0x00) # minimum attenuation # test oscillators and DUC for i in range(len(channel.oscillator)): oscillator = channel.oscillator[i] asf = 0 if i == 0: asf = 0x7fff # 6pi/4 phase oscillator.set_amplitude_phase_mu(asf=asf, pow=0xc000, clr=1) delay(1*us) # 3pi/4 channel.set_duc_phase_mu(0x6000) channel.set_duc_cfg(select=0, clr=1) self.duc_stb() delay(.1*ms) # settle link, pipeline and impulse response data = channel.get_dac_data() delay(1*us) channel.oscillator[0].set_amplitude_phase_mu(asf=0, pow=0xc000, clr=1) delay(.1*ms) sqrt2 = 0x5a81 # 0x7fff/sqrt(2) data_i = data & 0xffff data_q = (data >> 16) & 0xffff # allow ripple if (data_i < sqrt2 - 30 or data_i > sqrt2 or abs(data_i - data_q) > 2): raise ValueError("DUC+oscillator phase/amplitude test failed") if is_baseband: continue if channel.trf_read(0) & 0x7f != 0x68: raise ValueError("TRF identification failed") delay(.1*ms) delay(.2*ms) for data in channel.trf_mmap: channel.trf_write(data) channel.cal_trf_vco() delay(2*ms) # lock if not (self.get_sta() & (PHASER_STA_TRF0_LD << ch)): raise ValueError("TRF lock failure") delay(.1*ms) if channel.trf_read(0) & 0x1000: raise ValueError("TRF R_SAT_ERR") delay(.1*ms) channel.en_trf_out() # enable dac tx self.set_cfg(clk_sel=self.clk_sel)
[docs] @kernel def write8(self, addr, data): """Write data to FPGA register. :param addr: Address to write to (7 bit) :param data: Data to write (8 bit) """ rtio_output((self.channel_base << 8) | (addr & 0x7f) | 0x80, data) delay_mu(int64(self.t_frame))
[docs] @kernel def read8(self, addr) -> TInt32: """Read from FPGA register. :param addr: Address to read from (7 bit) :return: Data read (8 bit) """ rtio_output((self.channel_base << 8) | (addr & 0x7f), 0) response = rtio_input_data(self.channel_base) return response >> self.miso_delay
[docs] @kernel def write32(self, addr, data: TInt32): """Write 32 bit to a sequence of FPGA registers.""" for offset in range(4): byte = data >> 24 self.write8(addr + offset, byte) data <<= 8
[docs] @kernel def read32(self, addr) -> TInt32: """Read 32 bit from a sequence of FPGA registers.""" data = 0 for offset in range(4): data <<= 8 data |= self.read8(addr + offset) delay(20*us) # slack return data
[docs] @kernel def set_leds(self, leds): """Set the front panel LEDs. :param leds: LED settings (6 bit) """ self.write8(PHASER_ADDR_LED, leds)
[docs] @kernel def set_fan_mu(self, pwm): """Set the fan duty cycle. :param pwm: Duty cycle in machine units (8 bit) """ self.write8(PHASER_ADDR_FAN, pwm)
[docs] @kernel def set_fan(self, duty): """Set the fan duty cycle. :param duty: Duty cycle (0. to 1.) """ pwm = int32(round(duty*255.)) if pwm < 0 or pwm > 255: raise ValueError("duty cycle out of bounds") self.set_fan_mu(pwm)
[docs] @kernel def set_cfg(self, clk_sel=0, dac_resetb=1, dac_sleep=0, dac_txena=1, trf0_ps=0, trf1_ps=0, att0_rstn=1, att1_rstn=1): """Set the configuration register. Each flag is a single bit (0 or 1). :param clk_sel: Select the external SMA clock input :param dac_resetb: Active low DAC reset pin :param dac_sleep: DAC sleep pin :param dac_txena: Enable DAC transmission pin :param trf0_ps: Quadrature upconverter 0 power save :param trf1_ps: Quadrature upconverter 1 power save :param att0_rstn: Active low attenuator 0 reset :param att1_rstn: Active low attenuator 1 reset """ self.write8(PHASER_ADDR_CFG, ((clk_sel & 1) << 0) | ((dac_resetb & 1) << 1) | ((dac_sleep & 1) << 2) | ((dac_txena & 1) << 3) | ((trf0_ps & 1) << 4) | ((trf1_ps & 1) << 5) | ((att0_rstn & 1) << 6) | ((att1_rstn & 1) << 7))
[docs] @kernel def get_sta(self): """Get the status register value. Bit flags are: * :const:`PHASER_STA_DAC_ALARM`: DAC alarm pin * :const:`PHASER_STA_TRF0_LD`: Quadrature upconverter 0 lock detect * :const:`PHASER_STA_TRF1_LD`: Quadrature upconverter 1 lock detect * :const:`PHASER_STA_TERM0`: ADC channel 0 termination indicator * :const:`PHASER_STA_TERM1`: ADC channel 1 termination indicator * :const:`PHASER_STA_SPI_IDLE`: SPI machine is idle and data registers can be read/written :return: Status register """ return self.read8(PHASER_ADDR_STA)
[docs] @kernel def get_crc_err(self): """Get the frame CRC error counter. :return: The number of frames with CRC mismatches sind the reset of the device. Overflows at 256. """ return self.read8(PHASER_ADDR_CRC_ERR)
[docs] @kernel def set_sync_dly(self, dly): """Set SYNC delay. :param dly: DAC SYNC delay setting (0 to 7) """ if dly < 0 or dly > 7: raise ValueError("SYNC delay out of bounds") self.write8(PHASER_ADDR_SYNC_DLY, dly)
[docs] @kernel def duc_stb(self): """Strobe the DUC configuration register update. Transfer staging to active registers. This affects both DUC channels. """ self.write8(PHASER_ADDR_DUC_STB, 0)
[docs] @kernel def spi_cfg(self, select, div, end, clk_phase=0, clk_polarity=0, half_duplex=0, lsb_first=0, offline=0, length=8): """Set the SPI machine configuration :param select: Chip selects to assert (DAC, TRF0, TRF1, ATT0, ATT1) :param div: SPI clock divider relative to 250 MHz fabric clock :param end: Whether to end the SPI transaction and deassert chip select :param clk_phase: SPI clock phase (sample on first or second edge) :param clk_polarity: SPI clock polarity (idle low or high) :param half_duplex: Read MISO data from MOSI wire :param lsb_first: Transfer the least significant bit first :param offline: Put the SPI interfaces offline and don't drive voltages :param length: SPI transfer length (1 to 8 bits) """ if div < 2 or div > 257: raise ValueError("divider out of bounds") if length < 1 or length > 8: raise ValueError("length out of bounds") self.write8(PHASER_ADDR_SPI_SEL, select) self.write8(PHASER_ADDR_SPI_DIVLEN, (div - 2 >> 3) | (length - 1 << 5)) self.write8(PHASER_ADDR_SPI_CFG, ((offline & 1) << 0) | ((end & 1) << 1) | ((clk_phase & 1) << 2) | ((clk_polarity & 1) << 3) | ((half_duplex & 1) << 4) | ((lsb_first & 1) << 5))
[docs] @kernel def spi_write(self, data): """Write 8 bits into the SPI data register and start/continue the transaction.""" self.write8(PHASER_ADDR_SPI_DATW, data)
[docs] @kernel def spi_read(self): """Read from the SPI input data register.""" return self.read8(PHASER_ADDR_SPI_DATR)
[docs] @kernel def dac_write(self, addr, data): """Write 16 bit to a DAC register. :param addr: Register address :param data: Register data to write """ div = 34 # 100 ns min period t_xfer = self.core.seconds_to_mu((8 + 1)*div*4*ns) self.spi_cfg(select=PHASER_SEL_DAC, div=div, end=0) self.spi_write(addr) delay_mu(t_xfer) self.spi_write(data >> 8) delay_mu(t_xfer) self.spi_cfg(select=PHASER_SEL_DAC, div=div, end=1) self.spi_write(data) delay_mu(t_xfer)
[docs] @kernel def dac_read(self, addr, div=34) -> TInt32: """Read from a DAC register. :param addr: Register address to read from :param div: SPI clock divider. Needs to be at least 250 (1 ┬Ás SPI clock) to read the temperature register. """ t_xfer = self.core.seconds_to_mu((8 + 1)*div*4*ns) self.spi_cfg(select=PHASER_SEL_DAC, div=div, end=0) self.spi_write(addr | 0x80) delay_mu(t_xfer) self.spi_write(0) delay_mu(t_xfer) data = self.spi_read() << 8 delay(20*us) # slack self.spi_cfg(select=PHASER_SEL_DAC, div=div, end=1) self.spi_write(0) delay_mu(t_xfer) data |= self.spi_read() return data
[docs] @kernel def get_dac_temperature(self) -> TInt32: """Read the DAC die temperature. :return: DAC temperature in degree Celsius """ return self.dac_read(0x06, div=257) >> 8
[docs] @kernel def dac_sync(self): """Trigger DAC synchronisation for both output channels. The DAC sif_sync is de-asserts, then asserted. The synchronisation is triggered on assertion. By default, the fine-mixer (NCO) and QMC are synchronised. This includes applying the latest register settings. The synchronisation sources may be configured through the `syncsel_x` fields in the `dac` configuration dictionary (see `__init__()`). .. note:: Synchronising the NCO clears the phase-accumulator """ config1f = self.dac_read(0x1f) delay(.1*ms) self.dac_write(0x1f, config1f & ~int32(1 << 1)) self.dac_write(0x1f, config1f | (1 << 1))
[docs] @kernel def set_dac_cmix(self, fs_8_step): """Set the DAC coarse mixer frequency for both channels Use of the coarse mixer requires the DAC mixer to be enabled. The mixer can be configured via the `dac` configuration dictionary (see `__init__()`). The selected coarse mixer frequency becomes active without explicit synchronisation. :param fs_8_step: coarse mixer frequency shift in 125 MHz steps. This should be an integer between -3 and 4 (inclusive). """ # values recommended in data-sheet # 0 1 2 3 4 -3 -2 -1 vals = [0b0000, 0b1000, 0b0100, 0b1100, 0b0010, 0b1010, 0b0001, 0b1110] cmix = vals[fs_8_step%8] config0d = self.dac_read(0x0d) delay(.1*ms) self.dac_write(0x0d, (config0d & ~(0b1111 << 12)) | (cmix << 12))
[docs] @kernel def get_dac_alarms(self): """Read the DAC alarm flags. :return: DAC alarm flags (see datasheet for bit meaning) """ return self.dac_read(0x05)
[docs] @kernel def clear_dac_alarms(self): """Clear DAC alarm flags.""" self.dac_write(0x05, 0x0000)
[docs] @kernel def dac_iotest(self, pattern) -> TInt32: """Performs a DAC IO test according to the datasheet. :param pattern: List of four int32 containing the pattern :return: Bit error mask (16 bits) """ if len(pattern) != 4: raise ValueError("pattern length out of bounds") for addr in range(len(pattern)): self.dac_write(0x25 + addr, pattern[addr]) # repeat the pattern twice self.dac_write(0x29 + addr, pattern[addr]) delay(.1*ms) for ch in range(2): channel = self.channel[ch] channel.set_duc_cfg(select=1) # test # dac test data is i msb, q lsb data = pattern[2*ch] | (pattern[2*ch + 1] << 16) channel.set_dac_test(data) if channel.get_dac_data() != data: raise ValueError("DAC test data readback failed") delay(.1*ms) cfg = self.dac_read(0x01) delay(.1*ms) self.dac_write(0x01, cfg | 0x8000) # iotest_ena self.dac_write(0x04, 0x0000) # clear iotest_result delay(.2*ms) # let it rip # no need to go through the alarm register, # just read the error mask # self.clear_dac_alarms() alarms = self.get_dac_alarms() delay(.1*ms) # slack if alarms & 0x0080: # alarm_from_iotest errors = self.dac_read(0x04) delay(.1*ms) # slack else: errors = 0 self.dac_write(0x01, cfg) # clear config self.dac_write(0x04, 0x0000) # clear iotest_result return errors
[docs] @kernel def dac_tune_fifo_offset(self): """Scan through `fifo_offset` and configure midpoint setting. :return: Optimal `fifo_offset` setting with maximum margin to write pointer. """ # expect two or three error free offsets: # # read offset 01234567 # write pointer w # distance 32101234 # error free x xx config9 = self.dac_read(0x09) delay(.1*ms) good = 0 for o in range(8): # set new fifo_offset self.dac_write(0x09, (config9 & 0x1fff) | (o << 13)) self.clear_dac_alarms() delay(.1*ms) # run alarms = self.get_dac_alarms() delay(.1*ms) # slack if (alarms >> 11) & 0x7 == 0: # any fifo alarm good |= 1 << o # if there are good offsets accross the wrap around # offset for computations if good & 0x81 == 0x81: good = ((good << 4) & 0xf0) | (good >> 4) offset = 4 else: offset = 0 # calculate mean sum = 0 count = 0 for o in range(8): if good & (1 << o): sum += o count += 1 best = ((sum // count) + offset) % 8 self.dac_write(0x09, (config9 & 0x1fff) | (best << 13)) return best
[docs]class PhaserChannel: """Phaser channel IQ pair. A Phaser channel contains: * multiple oscillators (in the coredevice phy), * an interpolation chain and digital upconverter (DUC) on Phaser, * several channel-specific settings in the DAC: * quadrature modulation compensation QMC * numerically controlled oscillator NCO or coarse mixer CMIX, * the analog quadrature upconverter (in the Phaser-Upconverter hardware variant), and * a digitally controlled step attenuator. Attributes: * :attr:`oscillator`: List of five :class:`PhaserOscillator`. .. 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 non-zero, it is not sufficient to ensure that the sum in each quadrature is within range. .. note:: The interpolation filter on Phaser has an intrinsic sinc-like overshoot in its step response. That overshoot is a direct consequence of its near-brick-wall frequency response. For large and wide-band changes in oscillator parameters, the overshoot can lead to clipping or overflow after the interpolation. Either band-limit any changes in the oscillator parameters or back off the amplitude sufficiently. """ kernel_invariants = {"index", "phaser", "trf_mmap"} def __init__(self, phaser, index, trf): self.phaser = phaser self.index = index self.trf_mmap = TRF372017(trf).get_mmap() self.oscillator = [PhaserOscillator(self, osc) for osc in range(5)]
[docs] @kernel def get_dac_data(self) -> TInt32: """Get a sample of the current DAC data. The data is split accross multiple registers and thus the data is only valid if constant. :return: DAC data as 32 bit IQ. I/DACA/DACC in the 16 LSB, Q/DACB/DACD in the 16 MSB """ return self.phaser.read32(PHASER_ADDR_DAC0_DATA + (self.index << 4))
[docs] @kernel def set_dac_test(self, data: TInt32): """Set the DAC test data. :param data: 32 bit IQ test data, I/DACA/DACC in the 16 LSB, Q/DACB/DACD in the 16 MSB """ self.phaser.write32(PHASER_ADDR_DAC0_TEST + (self.index << 4), data)
[docs] @kernel def set_duc_cfg(self, clr=0, clr_once=0, select=0): """Set the digital upconverter (DUC) and interpolator configuration. :param clr: Keep the phase accumulator cleared (persistent) :param clr_once: Clear the phase accumulator for one cycle :param select: Select the data to send to the DAC (0: DUC data, 1: test data, other values: reserved) """ self.phaser.write8(PHASER_ADDR_DUC0_CFG + (self.index << 4), ((clr & 1) << 0) | ((clr_once & 1) << 1) | ((select & 3) << 2))
[docs] @kernel def set_duc_frequency_mu(self, ftw): """Set the DUC frequency. :param ftw: DUC frequency tuning word (32 bit) """ self.phaser.write32(PHASER_ADDR_DUC0_F + (self.index << 4), ftw)
[docs] @kernel def set_duc_frequency(self, frequency): """Set the DUC frequency in SI units. :param frequency: DUC frequency in Hz (passband from -200 MHz to 200 MHz, wrapping around at +- 250 MHz) """ ftw = int32(round(frequency*((1 << 30)/(125*MHz)))) self.set_duc_frequency_mu(ftw)
[docs] @kernel def set_duc_phase_mu(self, pow): """Set the DUC phase offset. :param pow: DUC phase offset word (16 bit) """ addr = PHASER_ADDR_DUC0_P + (self.index << 4) self.phaser.write8(addr, pow >> 8) self.phaser.write8(addr + 1, pow)
[docs] @kernel def set_duc_phase(self, phase): """Set the DUC phase in SI units. :param phase: DUC phase in turns """ pow = int32(round(phase*(1 << 16))) self.set_duc_phase_mu(pow)
[docs] @kernel def set_nco_frequency_mu(self, ftw): """Set the NCO frequency. This method stages the new NCO frequency, but does not apply it. Use of the DAC-NCO requires the DAC mixer and NCO to be enabled. These can be configured via the `dac` configuration dictionary (see `__init__()`). :param ftw: NCO frequency tuning word (32 bit) """ self.phaser.dac_write(0x15 + (self.index << 1), ftw >> 16) self.phaser.dac_write(0x14 + (self.index << 1), ftw)
[docs] @kernel def set_nco_frequency(self, frequency): """Set the NCO frequency in SI units. This method stages the new NCO frequency, but does not apply it. Use of the DAC-NCO requires the DAC mixer and NCO to be enabled. These can be configured via the `dac` configuration dictionary (see `__init__()`). :param frequency: NCO frequency in Hz (passband from -400 MHz to 400 MHz, wrapping around at +- 500 MHz) """ ftw = int32(round(frequency*((1 << 30)/(250*MHz)))) self.set_nco_frequency_mu(ftw)
[docs] @kernel def set_nco_phase_mu(self, pow): """Set the NCO phase offset. By default, the new NCO phase applies on completion of the SPI transfer. This also causes a staged NCO frequency to be applied. Different triggers for applying nco settings may be configured through the `syncsel_mixerxx` fields in the `dac` configuration dictionary (see `__init__()`). Use of the DAC-NCO requires the DAC mixer and NCO to be enabled. These can be configured via the `dac` configuration dictionary (see `__init__()`). :param pow: NCO phase offset word (16 bit) """ self.phaser.dac_write(0x12 + self.index, pow)
[docs] @kernel def set_nco_phase(self, phase): """Set the NCO phase in SI units. By default, the new NCO phase applies on completion of the SPI transfer. This also causes a staged NCO frequency to be applied. Different triggers for applying nco settings may be configured through the `syncsel_mixerxx` fields in the `dac` configuration dictionary (see `__init__()`). Use of the DAC-NCO requires the DAC mixer and NCO to be enabled. These can be configured via the `dac` configuration dictionary (see `__init__()`). :param phase: NCO phase in turns """ pow = int32(round(phase*(1 << 16))) self.set_nco_phase_mu(pow)
[docs] @kernel def set_att_mu(self, data): """Set channel attenuation. :param data: Attenuator data in machine units (8 bit) """ div = 34 # 30 ns min period t_xfer = self.phaser.core.seconds_to_mu((8 + 1)*div*4*ns) self.phaser.spi_cfg(select=PHASER_SEL_ATT0 << self.index, div=div, end=1) self.phaser.spi_write(data) delay_mu(t_xfer)
[docs] @kernel def set_att(self, att): """Set channel attenuation in SI units. :param att: Attenuation in dB """ # 2 lsb are inactive, resulting in 8 LSB per dB data = 0xff - int32(round(att*8)) if data < 0 or data > 0xff: raise ValueError("attenuation out of bounds") self.set_att_mu(data)
[docs] @kernel def get_att_mu(self) -> TInt32: """Read current attenuation. The current attenuation value is read without side effects. :return: Current attenuation in machine units """ div = 34 t_xfer = self.phaser.core.seconds_to_mu((8 + 1)*div*4*ns) self.phaser.spi_cfg(select=PHASER_SEL_ATT0 << self.index, div=div, end=0) self.phaser.spi_write(0) delay_mu(t_xfer) data = self.phaser.spi_read() delay(20*us) # slack self.phaser.spi_cfg(select=PHASER_SEL_ATT0 << self.index, div=div, end=1) self.phaser.spi_write(data) delay_mu(t_xfer) return data
[docs] @kernel def trf_write(self, data, readback=False): """Write 32 bits to quadrature upconverter register. :param data: Register data (32 bit) containing encoded address :param readback: Whether to return the read back MISO data """ div = 34 # 50 ns min period t_xfer = self.phaser.core.seconds_to_mu((8 + 1)*div*4*ns) read = 0 end = 0 clk_phase = 0 if readback: clk_phase = 1 for i in range(4): if i == 0 or i == 3: if i == 3: end = 1 self.phaser.spi_cfg(select=PHASER_SEL_TRF0 << self.index, div=div, lsb_first=1, clk_phase=clk_phase, end=end) self.phaser.spi_write(data) data >>= 8 delay_mu(t_xfer) if readback: read >>= 8 read |= self.phaser.spi_read() << 24 delay(20*us) # slack return read
[docs] @kernel def trf_read(self, addr, cnt_mux_sel=0) -> TInt32: """Quadrature upconverter register read. :param addr: Register address to read (0 to 7) :param cnt_mux_sel: Report VCO counter min or max frequency :return: Register data (32 bit) """ self.trf_write(0x80000008 | (addr << 28) | (cnt_mux_sel << 27)) # single clk pulse with ~LE to start readback self.phaser.spi_cfg(select=0, div=34, end=1, length=1) self.phaser.spi_write(0) delay((1 + 1)*34*4*ns) return self.trf_write(0x00000008 | (cnt_mux_sel << 27), readback=True)
[docs] @kernel def cal_trf_vco(self): """Start calibration of the upconverter (hardware variant) VCO. TRF outputs should be disabled during VCO calibration. """ self.trf_write(self.trf_mmap[1] | (1 << 31))
[docs] @kernel def en_trf_out(self, rf=1, lo=0): """Enable the rf/lo outputs of the upconverter (hardware variant). :param rf: 1 to enable RF output, 0 to disable :param lo: 1 to enable LO output, 0 to disable """ data = self.trf_read(0xc) delay(0.1 * ms) # set RF and LO output bits data = data | (1 << 12) | (1 << 13) | (1 << 14) # clear to enable output if rf == 1: data = data ^ (1 << 14) if lo == 1: data = data ^ ((1 << 12) | (1 << 13)) self.trf_write(data)
[docs]class PhaserOscillator: """Phaser IQ channel oscillator (NCO/DDS). .. note:: Latencies between oscillators within a channel and between oscillator paramters (amplitude and phase/frequency) are deterministic (with respect to the 25 MS/s sample clock) but not matched. """ kernel_invariants = {"channel", "base_addr"} def __init__(self, channel, index): self.channel = channel self.base_addr = ((self.channel.phaser.channel_base + 1 + 2*self.channel.index) << 8) | index
[docs] @kernel def set_frequency_mu(self, ftw): """Set Phaser MultiDDS frequency tuning word. :param ftw: Frequency tuning word (32 bit) """ rtio_output(self.base_addr, ftw)
[docs] @kernel def set_frequency(self, frequency): """Set Phaser MultiDDS frequency. :param frequency: Frequency in Hz (passband from -10 MHz to 10 MHz, wrapping around at +- 12.5 MHz) """ ftw = int32(round(frequency*((1 << 30)/(6.25*MHz)))) self.set_frequency_mu(ftw)
[docs] @kernel def set_amplitude_phase_mu(self, asf=0x7fff, pow=0, clr=0): """Set Phaser MultiDDS amplitude, phase offset and accumulator clear. :param asf: Amplitude (15 bit) :param pow: Phase offset word (16 bit) :param clr: Clear the phase accumulator (persistent) """ data = (asf & 0x7fff) | ((clr & 1) << 15) | (pow << 16) rtio_output(self.base_addr + (1 << 8), data)
[docs] @kernel def set_amplitude_phase(self, amplitude, phase=0., clr=0): """Set Phaser MultiDDS amplitude and phase. :param amplitude: Amplitude in units of full scale :param phase: Phase in turns :param clr: Clear the phase accumulator (persistent) """ asf = int32(round(amplitude*0x7fff)) if asf < 0 or asf > 0x7fff: raise ValueError("amplitude out of bounds") pow = int32(round(phase*(1 << 16))) self.set_amplitude_phase_mu(asf, pow, clr)