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System Configuration

The SpiNNaker2 STM interface provides utilities for configuring voltage and frequency settings on the board.

Voltage Configuration

Setting Bus Voltage

from spinnaker2_stm.configure import set_bus_voltage

# Set voltage for 0.5V power lane
set_bus_voltage(domain=0, voltage=0.5)

# Set voltage for 0.8V power lane
set_bus_voltage(domain=1, voltage=0.8)

The set_bus_voltage function accepts:

  • domain: Power lane selection (0 for 0.5V, 1 for 0.8V)
  • voltage: Target voltage value
  • For 0.5V domain: must be between 0.3V and 0.8V
  • For 0.8V domain: valid range depends on hardware
  • show_output: Whether to print operation feedback (default: True)
  • ser_path: Serial interface path (default: "/dev/ttyACM0")

Frequency Configuration

Setting PE and NoC Frequencies

from spinnaker2_stm.configure import set_pl_and_frequency

# Configure PE and NoC frequencies
set_pl_and_frequency(
    pe_pl=1,      # PE power lane
    pe_freq=125,  # PE frequency in MHz
    noc_pl=1,     # NoC power lane
    noc_freq=125  # NoC frequency in MHz
)

The system will:

  1. Load or create a frequency lookup table
  2. Generate the necessary configuration code
  3. Update the relevant system files with new timing parameters

Frequency Code Generation

For lower-level frequency configuration, use freq_code_gen:

from spinnaker2_stm.configure import freq_code_gen

freq_cfg = [
    125,    # PE frequency (MHz)
    125,    # NoC frequency (MHz)
    1,      # PE division lane
    1,      # NoC division lane
    0x1234, # PLL config 0
    0x5678, # PLL config 1
    1,      # div0
    1,      # div1
    1,      # div2
    1       # div3
]

freq_code_gen(freq_cfg, has_timer=True)

This will:

  • Update PLL configuration registers
  • Set PE and NoC clock dividers
  • Configure power lane settings
  • Update timer frequencies if required

Reference Clock

The system uses a reference clock of 100 MHz (JIB1_CLK_REF). This is used as the base for all frequency calculations.

Error Handling

The configuration functions include basic error checking:

  • Invalid voltage ranges
  • Invalid power domain selections
  • File access errors during configuration updates

For example: 

# This will raise an error
set_bus_voltage(domain=0, voltage=0.2)  # Error: voltage below 0.3V minimum