I2C switches on satellites?

dtsevas

Previously, we connected all of our DIO_SMA boards to the DRTIO master's EEM slots starting from slot 0. In that config, we successfully set their channels' directions like this:

from artiq.coredevice.kasli_i2c import port_mapping
KASLI_I2C_BOARD_TO_PORT_MAPPING = [port%8 for port in port_mapping.values()]
DIO_SMA_BUS_NUMBER = 0
DIO_SMA_BUS_ADDRESS = 0x7c
[...]
        board = 0 # can be any value smaller than # DIO_SMA boards
        if board < 8:
            i2c_sw = self.i2c_switch0
        else:
            i2c_sw = self.i2c_switch1
        i2c_addr = KASLI_I2C_BOARD_TO_PORT_MAPPING[board]
        delay(1*us)
        i2c_sw.set(channel = i2c_addr)
        delay(1*us)
        i2c_write_byte(
            busno   = DIO_SMA_BUS_NUMBER,
            busaddr = DIO_SMA_BUS_ADDRESS,
            data    = 0,
        )
        delay(1*us)
        i2c_sw.unset()

Now, we moved some DIO_SMA boards to a satellite starting from EEM slot 2. The above code crashes with:

Core Device Traceback:
Traceback (most recent call first):
  File "<artiq>/coredevice/i2c.py", line 67, column 13, in artiq.coredevice.i2c.i2c_write_byte(..., ...)
    raise I2CError("failed to ack bus address")
    ^
  File "StartUpKernel.py", line 67, in ... artiq_run_StartUpKernel.StartUpKernel.init<artiq_run_StartUpKernel.StartUpKernel>(...) (RA=+0x20c)
    i2c_write_byte(
  File "StartUpKernel.py", line 116, in artiq_run_StartUpKernel.StartUpKernel.run(..., ...) (inlined)
    self.init()
  File "<artiq>/coredevice/i2c.py", line 0, in ?? (RA=+0x1bd4)
    <unknown>
artiq.coredevice.exceptions.I2CError(0): failed to ack bus address

End of Core Device Traceback

Traceback (most recent call last):
  File "/opt/m1/workspace/artiq-testing/development/09_StartUpKernel/run.py", line 65, in <module>
    run()
  File "/opt/m1/workspace/artiq-testing/development/09_StartUpKernel/run.py", line 59, in run
    raise exn
  File "/opt/m1/workspace/artiq-testing/development/09_StartUpKernel/run.py", line 50, in run
    exp_inst.run()
  File "/opt/m1/workspace/artiq/artiq/language/core.py", line 54, in run_on_core
    return getattr(self, arg).run(run_on_core, ((self,) + k_args), k_kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/m1/workspace/artiq/artiq/coredevice/core.py", line 177, in run
    self._run_compiled(kernel_library, embedding_map, symbolizer, demangler)
  File "/opt/m1/workspace/artiq/artiq/coredevice/core.py", line 166, in _run_compiled
    self.comm.serve(embedding_map, symbolizer, demangler)
  File "/opt/m1/workspace/artiq/artiq/coredevice/comm_kernel.py", line 739, in serve
    self._serve_exception(embedding_map, symbolizer, demangler)
  File "/opt/m1/workspace/artiq/artiq/coredevice/comm_kernel.py", line 721, in _serve_exception
    raise python_exn
artiq.coredevice.exceptions.I2CError: failed to ack bus address

Our device_db.py only contains these i2c-related entries:

device_db = {
    "core": {
        "type": "local",
        "module": "artiq.coredevice.core",
        "class": "Core",
        "arguments": {
            "host": core_addr,
            "ref_period": 1e-09,
            "analyzer_proxy": "core_analyzer",
            "target": "cortexa9",
            "satellite_cpu_targets": {}
        },
    },
[...]
    "i2c_switch0": {
        "type": "local",
        "module": "artiq.coredevice.i2c",
        "class": "I2CSwitch",
        "arguments": {"address": 0xe0}
    },
    "i2c_switch1": {
        "type": "local",
        "module": "artiq.coredevice.i2c",
        "class": "I2CSwitch",
        "arguments": {"address": 0xe2}
    },
}

Clearly, we are not talking to the appropriate i2c switches. How can we fix this?

Here is our system description file for the satellite with the DIO_SMA boards:

{
    "target": "kasli_soc",
    "hw_rev": "v1.1",
    "base": "use_drtio_role",
    "drtio_role": "satellite",
    "enable_wrpll": false,
    "sed_lanes": 32,
    "min_artiq_version": "8.0",
    "core_addr": "192.168.1.30",
    "variant": "crate_cryo_rack_ao_dio_kasli_soc_v1.1_artiq_zynq_master_63157588bb8ed214bc9f24ade2d09b4ddefada03_drtio_satellite_wrpll_False_sed_32_periph_dio_sma_4_fastino_1_addr_192.168.1.30",
    "peripherals": [
        {
            "type": "fastino",
            "hw_rev": "v1.3",
            "ports": [
                0
            ]
        },
        {
            "type": "dio",
            "board": "DIO_SMA",
            "hw_rev": "v1.4.1",
            "ports": [
                2
            ],
            "bank_direction_low": "input",
            "bank_direction_high": "input"
        },
        {
            "type": "dio",
            "board": "DIO_SMA",
            "hw_rev": "v1.4.1",
            "ports": [
                3
            ],
            "bank_direction_low": "input",
            "bank_direction_high": "input"
        },
        {
            "type": "dio",
            "board": "DIO_SMA",
            "hw_rev": "v1.4.1",
            "ports": [
                4
            ],
            "bank_direction_low": "input",
            "bank_direction_high": "input"
        },
        {
            "type": "dio",
            "board": "DIO_SMA",
            "hw_rev": "v1.4.1",
            "ports": [
                5
            ],
            "bank_direction_low": "input",
            "bank_direction_high": "input"
        }
    ]
}

claytonho

i think there was previously a similar issue on the forum: https://forum.m-labs.hk/d/622-eeprom-aliasing-when-using-drtio

dtsevas

claytonho Thank you very much. Do you know if the bus address for talking to the DIO_SMA boards depends on the DRTIO destination?

        i2c_write_byte(
            busno   = 65536, # from `device_db.py`, depends on DRTIO destination
            busaddr = 0x7c, # always the same?
            data    = 0,
        )

For others: If one creates device_db.py with artiq/commit/94bbad9d53eefc84e08ce60444eb4867995fd918 or later, then each satellite's i2c switches appear as pasted below.

# DEST#1 peripherals

device_db["i2c_switch0_1"] = {
    "type": "local",
    "module": "artiq.coredevice.i2c",
    "class": "I2CSwitch",
    "arguments": {"address": 0xe0, "busno": 65536}
}
device_db["i2c_switch1_1"] = {
    "type": "local",
    "module": "artiq.coredevice.i2c",
    "class": "I2CSwitch",
    "arguments": {"address": 0xe2, "busno": 65536}
}

bukehu

Hi!
The I2C buss address are fixed by hardware, thus should not depends on the DRTIO configuration.

dtsevas

bukehu I tried what you say, but it didn't work. In the end, I discovered that DIO_SMA boards have small switches where one can set the default channel direction by hand. We don't need to change the channel directions more than once per year, so we will just work with that.