1.7 SpaceWire Loopback Example

This example shows how to configure the SpaceWire peripheral to send and receive multiple packets. It uses multiple receive buffer to exercise in an optimize way the 3 states (NEXT, CURRENT, PREVIOUS) for packet reception.

Building The Application

The parent folder for all the MPLABX IDE projects for this application is given below:

  • Application Path : apps\spw\spw_loopback\firmware

To build the application, refer to the table below and open the appropriate project file in MPLABX IDE.

Project NameDescription
sam_rh707_ek.XSAM RH707 Evaluation Kit board

MPLAB Harmony Configurations

Refer to the MHC project graph for the components used and the respective configuration options.

Hardware Setup

  1. Project sam_rh707_ek.X

    • Hardware Used

      • SAM RH707 Evaluation Kit
      • SpaceWire cable

    • Hardware Setup

      • Connect the USB port (USB DEBUG) on the board to the computer using a micro USB cable.
        • If the board embedded debugger is not used, connect the debugger probe on DEBUG connector (J5).
      • Connect the two SpaceWire link on the board to each other using a SpaceWire cable.

      Note : This example can also be tested with SpaceWire links configured in TTL:

      • Pin configuration must be modified in Harmony Configuration to set unused pin in an other function than SpaceWire.
      • Evaluation kit board must be modified like described in the user guide.

Running The Application

  1. Open the Terminal application (Ex.:Tera term) on the computer.

  2. Connect to the Virtual COM port and configure the serial settings as follows:

    • Baud : 115200
    • Data : 8 Bits
    • Parity : None
    • Stop : 1 Bit
    • Flow Control : None

  3. Build and Program the application using the MPLABX IDE.

  4. See the following message in the console.

    -----------------------------------------------------------
SPW loopback example
-----------------------------------------------------------
Wait for both SWP link switch to run state
SPW Link in Run state
TX time=3058836 us, for 25000000 bytes
Effective rate=65 Mb/s
Average RX process time = 39 us
Rx sequence errors = 0
End of transfer