artiq/artiq/coredevice/mirny.py

"""RTIO driver for Mirny (4 channel GHz PLLs)
"""

from artiq.language.core import kernel, delay
from artiq.language.units import us

from numpy import int32

from artiq.coredevice import spi2 as spi


SPI_CONFIG = (
    0 * spi.SPI_OFFLINE
    | 0 * spi.SPI_END
    | 0 * spi.SPI_INPUT
    | 1 * spi.SPI_CS_POLARITY
    | 0 * spi.SPI_CLK_POLARITY
    | 0 * spi.SPI_CLK_PHASE
    | 0 * spi.SPI_LSB_FIRST
    | 0 * spi.SPI_HALF_DUPLEX
)

# SPI clock write and read dividers
SPIT_WR = 4
SPIT_RD = 16

SPI_CS = 1

WE = 1 << 24


class Mirny:
    """
    Mirny PLL-based RF generator.

    :param spi_device: SPI bus device
    :param refclk: Reference clock (SMA, MMCX or on-board 100 MHz oscillator)
        frequency in Hz
    :param clk_sel: Reference clock selection.
        valid options are: 0 - internal 100MHz XO; 1 - front-panel SMA; 2 -
        internal MMCX
    :param core_device: Core device name (default: "core")
    """

    kernel_invariants = {"bus", "core"}

    def __init__(self, dmgr, spi_device, refclk=100e6, clk_sel=0, core_device="core"):
        self.core = dmgr.get(core_device)
        self.bus = dmgr.get(spi_device)

        self.refclk = refclk
        assert 10 <= self.refclk / 1e6 <= 600, "Invalid refclk"

        self.clk_sel = clk_sel & 0b11
        assert 0 <= self.clk_sel <= 3, "Invalid clk_sel"

        # TODO: support clk_div on v1.0 boards

    @kernel
    def read_reg(self, addr):
        """Read a register"""
        self.bus.set_config_mu(
            SPI_CONFIG | spi.SPI_INPUT | spi.SPI_END, 24, SPIT_RD, SPI_CS
        )
        self.bus.write((addr << 25))
        return self.bus.read() & int32(0xFFFF)

    @kernel
    def write_reg(self, addr, data):
        """Write a register"""
        self.bus.set_config_mu(SPI_CONFIG | spi.SPI_END, 24, SPIT_WR, SPI_CS)
        self.bus.write((addr << 25) | WE | ((data & 0xFFFF) << 8))

    @kernel
    def init(self, blind=False):
        """
        Initialize and detect Mirny.

        :param blind: Do not attempt to verify presence and compatibility.
        """
        if not blind:
            reg0 = self.read_reg(0)
            if reg0 & 0b11 != 0b11:
                raise ValueError("Mirny HW_REV mismatch")
            if (reg0 >> 2) & 0b11 != 0b00:
                raise ValueError("Mirny PROTO_REV mismatch")
            delay(100 * us)  # slack

        # select clock source
        self.write_reg(1, (self.clk_sel << 4))
        delay(1000 * us)

    @kernel
    def set_att_mu(self, channel, att):
        """Set digital step attenuator in machine units.

        :param att: Attenuation setting, 8 bit digital.
        """
        self.bus.set_config_mu(SPI_CONFIG | spi.SPI_END, 16, SPIT_WR, SPI_CS)
        self.bus.write(((channel | 8) << 25) | (att << 16))

    @kernel
    def write_ext(self, addr, length, data):
        """Perform SPI write to a prefixed address"""
        self.bus.set_config_mu(SPI_CONFIG, 8, SPIT_WR, SPI_CS)
        self.bus.write(addr << 25)
        self.bus.set_config_mu(SPI_CONFIG | spi.SPI_END, length, SPIT_WR, SPI_CS)
        if length < 32:
            data <<= 32 - length
        self.bus.write(data)