nix-servo/fast-servo/pyfastservo/si5340.py

# This file is part of Fast Servo Software Package.
#
# Copyright (C) 2023 Jakub Matyas
# Warsaw University of Technology <jakubk.m@gmail.com>
# SPDX-License-Identifier: GPL-3.0-or-later
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
# 
# This program is distributed in the hope that it will be useful, 
# but WITHOUT ANY WARRANTY; without even the implied warranty of 
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <https://www.gnu.org/licenses/>.

from smbus2 import SMBus

BUS_NO = 0
IC_ADDR = 0x74

PAGE_ADDR = 0x1

OUT0_MUX_SEL_ADDR = 0x15
OUT1_MUX_SEL_ADDR = 0x1A
OUT2_MUX_SEL_ADDR = 0x29
OUT3_MUX_SEL_ADDR = 0x2E

OUT2_AMPL_ADDR = 0x28

OUT3_PDN_ADDR = 0x2B
OUT3_FORMAT_ADDR = 0x2C
OUT3_AMPL_ADDR = 0x2D


N1_DIVIDER_UPDATE_ADDR = 0x17

data_to_write = 0
clk_out_addr = [
    OUT0_MUX_SEL_ADDR,
    OUT1_MUX_SEL_ADDR,
    OUT2_MUX_SEL_ADDR,
    OUT3_MUX_SEL_ADDR,
]

def configure_si5340():
    with SMBus(BUS_NO) as bus:

        bus.write_byte_data(IC_ADDR, PAGE_ADDR, 0x0)  # setting page to page 0

        # read device id
        low_word = bus.read_byte_data(IC_ADDR, 0x2)
        high_word = bus.read_byte_data(IC_ADDR, 0x3)

        print(f"DEV ID: 0x{high_word:2x}{low_word:2x}")

        data_to_write = 0x1
        bus.write_byte_data(
            IC_ADDR, PAGE_ADDR, data_to_write
        )  # change to page 1 for output settings

        readback = bus.read_byte_data(IC_ADDR, PAGE_ADDR)
        if data_to_write != readback:
            raise ValueError(f"Failed to set page.")

        for addr in clk_out_addr:
            bus.write_byte_data(IC_ADDR, addr, 1)  # set source to N1

        bus.write_byte_data(IC_ADDR, OUT2_AMPL_ADDR, 13)
        readback = bus.read_byte_data(IC_ADDR, OUT2_AMPL_ADDR)
        # if data_to_write != readback:
        #     raise ValueError(f"Problematic read: {readback}.")

        bus.write_byte_data(IC_ADDR, OUT2_AMPL_ADDR, 0x6B)  # setting OUT2 to LVDS25

        bus.write_byte_data(IC_ADDR, OUT3_FORMAT_ADDR, 0xCC)  # SETTING out3 to LVCMOS 18
        # bus.write_byte_data(IC_ADDR, 0x2E, 0x09)		# SETTING out3 to LVCMOS 33

        readback = bus.read_byte_data(IC_ADDR, OUT3_PDN_ADDR)
        print(f"Si5340 OUTx_PDN CLK3: 0x{readback}")

        readback = bus.read_byte_data(IC_ADDR, OUT3_FORMAT_ADDR)
        print(f"Si5340 OUTx_FORMAT CLK3: 0x{readback}")

        readback = bus.read_byte_data(IC_ADDR, OUT3_AMPL_ADDR)
        print(f"Si5340 OUTx_AMPL CLK3: 0x{readback}")

        readback = bus.read_byte_data(IC_ADDR, OUT3_MUX_SEL_ADDR)
        print(f"Si5340 OUTx_CM CLK3: 0x{readback}")

        bus.write_byte_data(
            IC_ADDR, PAGE_ADDR, 0x3
        )  # setting page to 3 to change dividers values

        n1_numerator = [0x0, 0x0, 0x0, 0x60, 0x22, 0x0]
        n1_numerator_10M = [0x0, 0x0, 0x0, 0xC0, 0x57, 0x1]
        n1_num_addr = [0x0D, 0x0E, 0x0F, 0x10, 0x11, 0x12]
        n1_denom_addr = [0x13, 0x14, 0x15, 0x16]
        for addr, value in zip(n1_num_addr, n1_numerator):
            bus.write_byte_data(IC_ADDR, addr, value)

        bus.write_byte_data(IC_ADDR, N1_DIVIDER_UPDATE_ADDR, 1)

        for addr in n1_num_addr:
            readback = bus.read_byte_data(IC_ADDR, addr)
            print(f"Numerator buffer: 0x{readback:02x}")

        for addr in n1_denom_addr:
            readback = bus.read_byte_data(IC_ADDR, addr)
            print(f"Denominator buffer: 0x{readback:02x}")

        bus.write_byte_data(IC_ADDR, PAGE_ADDR, 0x0)  # setting page to page 0

if __name__ == "__main__":
    configure_si5340()