DMGT (board management)

This subsystem is used for general board control. It is always present and always enabled, but its exact capabilities must be queried.

DMGT_GET_CAPABILITIES

Returns capabilities of the DMGT subsystem. Always supported.

  • subsystem: 0x01 (DMGT)
  • command type: 0x02 (short)
  • port: N/A, always 0
  • command payload: none
  • response payload: 32-bit capabilities word
    • bit 0: power control (DMGT_POWER_ON, DMGT_POWER_OFF)
    • bit 1: config reset (DMGT_CONFIG_RESET)
    • bit 2: user reset (DMGT_USER_RESET)
    • bit 3: query DONE (DMGT_QUERY_DONE)
    • bit 5: query power state (DMGT_QUERY_POWER_STATE)
    • bit 6: power supply monitoring (DMGT_GET_POWER_SUPPLY_*)

DMGT_POWER_ON

Turns on power to the rest of the board.

  • subsystem: 0x01 (DMGT)
  • command type: 0x03 (short)
  • port: N/A, always 0
  • command payload: none
  • response payload: none

DMGT_POWER_OFF

Turns off power to the rest of the board.

Note that on some boards (eg. iCEblink40), this command only momentarily switches off power, turning it back on within half a second or so.

  • subsystem: 0x01 (DMGT)
  • command type: 0x04 (short)
  • port: N/A, always 0
  • command payload: none
  • response payload: none

DMGT_CONFIG_RESET

Sets the state of the FPGA configuration reset pin (eg. PROG_B on Xilinx devices).

  • subsystem: 0x01 (DMGT)
  • command type: 0x06 (short)
  • port: N/A, always 0
  • command payload: 1 byte
    • 0: deassert reset to the device
    • 1: assert reset to the device
  • response payload: none

Note that the reset here is active-high, which is the inverse of the state of the actual PROG_B pin.

DMGT_USER_RESET

Sets the state of the user reset pin on the FPGA, if the board has one.

  • subsystem: 0x01 (DMGT)
  • command type: 0x07 (short)
  • port: N/A, always 0
  • command payload: 1 byte
    • 0: deassert reset to the device
    • 1: assert reset to the device
  • response payload: none

DMGT_QUERY_DONE

Returns the state of the DONE pin on the FPGA.

  • subsystem: 0x01 (DMGT)
  • command type: 0x08 (short)
  • port: N/A, always 0
  • command payload: none
  • response payload: 1 byte (the LSB is the state of the DONE pin)

DMGT_QUERY_POWER_STATE

Returns the state of the board's power supply.

  • subsystem: 0x01 (DMGT)
  • command type: 0x0c (short)
  • port: N/A, always 0
  • command payload: none
  • response payload: 1 byte
    • 0: power is off
    • 1: power is on

DMGT_GET_POWER_SUPPLY_COUNT

Returns the number of power supplies on the board that can be monitored.

  • subsystem: 0x01 (DMGT)
  • command type: 0x0d (short)
  • port: N/A, always 0
  • command payload: none
  • response payload: 32-bit word (number of power supplies)

DMGT_GET_POWER_SUPPLY_DATA

Returns the current state of the given power supply.

  • subsystem: 0x01 (DMGT)
  • command type: 0x0d (short)
  • port: N/A, always 0
  • command payload: 1 byte (power supply index)
  • response payload: 5 32-bit words:
    • word 0: raw voltage value
    • word 1: raw current value
    • word 2: raw power value
    • word 3: raw temperature value
    • word 4: status; status bits for all power supplies on the board (up to 8 of them) are packed into this word, 4 bits for each supply:
      • bit 0: power supply is on
      • bit 1: power supply voltage out of spec
      • bit 2: overcurrent condition
      • bit 3: overtemperature condition

All sensor values returned are unsigned integers which need to have the conversion factor applied to them.

DMGT_GET_POWER_SUPPLY_PROPERTIES

Returns the scaling factors that should be applied to the raw sensor values of the given power supply.

  • subsystem: 0x01 (DMGT)
  • command type: 0x0f (short)
  • port: N/A, always 0
  • command payload: 1 byte (power supply index)
  • response payload: 4 32-bit words:
    • word 0: voltage scaling factor (in µV units)
    • word 1: current scaling factor (in µA units)
    • word 2: power scaling factor (in µW units)
    • word 3: temperature scaling factor (in µK units)

The raw values from the sensors should be multiplied by these constant scaling factors to obtain the actual physical values.

DMGT_GET_POWER_SUPPLY_LABEL

Returns the free-form label string describing the given power supply.

  • subsystem: 0x01 (DMGT)
  • command type: 0x10 (short)
  • port: N/A, always 0
  • command payload: 1 byte (power supply index)
  • response payload: 32-byte string (NUL-terminated)