TC-Specs/Navigation/pps.txt at master · techcompliant/TC-Specs · GitHub

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   \\ TALON NAVIGATION //
   "walk among the stars"


DCPU-16 Hardware Info:
    Name: Pulsar Positioning System (navigator)
    ID: 0xfce26509
    Version: 0xb01e
    Manufacturer: 0x982d3e46 (TALON NAVIGATION SYSTEMS)

Description:
    PPS can determine it's position using radio-wave and x-ray signals
    from pulsars. PPS can function anywhere in Milky Way galaxy, but it
    requires a dish antenna of 2m in diameter. Talon is the only provider
    of PPS systems that can utilize over 2000 beacon pulsars for
    measuring position.

    Talon PPS hardware provides the fastest signal acquisition on market.
    It can cold start (no time, no position, no ephemeris) in <55 seconds
    and measure new position data every 8-25 seconds.

    Talon provides both global and local coordinate systems. Global
    coordinates are represented as 64bit integers. Local coordinates are
    represented as 16bit integers with configurable origin.

    Talon PPS functions by storing latest position measurement results in
    internal memory array. Interrupts GET_LOCAL_COORDINATES and
    STORE_GLOBAL_COORDINATES can be used to access the data.

Interrupt behavior:
    When a HWI is received by the PPS, it reads the A register and does one
    of the following actions:

    0: CONFIGURE_LOCAL_ORIGIN
       Reads Global Coordinate Array pointed by register B from ram and uses
       it as the new origin for local coordinates.

       Halts the DCPU-16 for 12 cycles.

       Register C is set with the operation status:
          0x0000       : Success
          0xffff       : Equipment malfunction

    1: GET_LOCAL_COORDINATES
       Stores the latest measured position -relative to Local Origin, to
       DCPU-16 registers X, Y and Z.

         X: (UINT16) x-coordinate (unit 1km)
         Y: (UINT16) y-coordinate (unit 1km)
         Z: (UINT16) z-coordinate (unit 1km)

       Coordinates that are outside the UINT16 range are replaced with
       the closest presentable value (0x0000 or 0xffff) and operation status
       in register C is set to 0x0002.

       Register C is set with the operation status:
          0x0000       : Success
          0x0001       : Success, but reduced accuracy
          0x0002       : Success, but out of range
          0x8000       : Failure, no pulsar fix
          0xffff       : Failure, equipment malfunction

    2: STORE_GLOBAL_COORDINATES
       Register B is used as the target address to write the latest measured
       position as Global Coordinate Array to DCPU ram.

       Halts the DCPU-16 for 12 cycles.

       Register C is set with the operation status:
          0x0000       : Success
          0x0001       : Success, but reduced accuracy
          0x8000       : Failure, no pulsar fix
          0xffff       : Failure, equipment malfunction

    4: CONFIGURE_INTERRUPTS
       Enables interrupts and sets the message to X if X is anything other
       than 0, disables interrupts if X is 0. When interrupts are enabled,
       the PPS will trigger an interrupt on the DCPU-16 whenever new position
       data is available in PPS's internal memory.

Global Coordinate Array:
    word  0 -  3: UINT64 X-Coordinate
    word  4 -  7: UINT64 Y-Coordinate
    word  8 - 11: UINT64 Z-Coordinate

    Values are stored from MSB to LSB.