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AM4377: PRU 4-channel current sense with SDDF

Kzk
Genius 5785 points
Part Number: AM4377

Hello,

In order to control two three phase motors in our system, PRU-ICSS needs to process Sigma Delta Decimation Filtering and perform four current sensing. (I1u, I1v, I2u and I2v)

The SDDF processing channel is described in the following documents.

"Three channels are used for current (5, 6, & 7), channel '1' is used for voltage (which is disabled by default)."

C:\ti\PRU-ICSS-Industrial_Drives_01.00.00.00\interfaces\sddf\doc\SigmaDelta_am437x_design.pdf

Can PRU-ICSS perform four current sensing simply by setting arguments to the driver API without customizing the firmware or the driver source code?

Regards,
Kazu

  • 0
    TI__Guru**** 393215 points
    The Industrial team have been notified. They will respond here.
  • 0 in reply to Biser Gatchev-XID
    TI__Expert 7570 points

    Hi

     

    The channel that is reserved for meant for voltage measurment can be used as a 4th current channel, however, this channel does not have overcurrent detection .

    When the SDDF is operated in the continuous current mode, the voltage channel is enabled by default. Thus, there would be 4 channels are available. 

    In triggered mode, however, voltage channel is disabled .

     

    Can you use the continuous mode? 

     

    In the current Drives 1.0.0 release the pinmux is configured for just 2 current channels, in this case , the pinmux settings will need to be changed to support the additional channels.

     

    David

  • 0 in reply to David Zaucha
    Genius 5785 points

    Hello David,

    Thank you for your answer. I'd like to use SDDF in triggered mode and start it when PWM compare reaches a certain value. Also, I'll use it for position detection, not overcurrent detection.

    Even if I customize the driver (Cortex-A9 software) and enable the 3rd current channel by PinMux, it seems to be difficult to control two motors with just three current values in my case. I hope four current channels for triggerd mode. Please let me know if you have an update plan for PRU-ICSS F/W for SDDF.

    Regards,
    Kazu

  • 0 in reply to Kzk
    TI__Expert 7570 points

    Kazu

    Let me check with the development team.

    David

  • 0 in reply to David Zaucha
    TI__Expert 7570 points
    Kazu

    I am sorry, this development is not planned for the near future. If you wish to investigate the implementation, the driver and firmware are provided in source code along with the SDDF design document and the API guide in C:\ti\PRU-ICSS-Industrial_Drives_01.00.00.00\interfaces\sddf .

    David
  • 0 in reply to David Zaucha
    Genius 5785 points

    Hello David,

    I understand. Thank you anyway.

    Regards,

    Kazu