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TMS320F280049C: event synchronization over FSI

Art Mecina
Genius 16795 points
Part Number: TMS320F280049C
Other Parts Discussed in Thread: C2000WARE,

Hi Team,

Good day.

Our customer is using the MCU of TMS320F280049C. In the SPRACM3D, a method for Event Synchronization over FSI is provided, In which only the ping packet is sent/ received and the packet is received by Slave MCU, then the same ping packet is sent to next slave MCU directly without changes. In the C2000Ware Example Project-> f28004x_fsi_daisychain_epwmsync-> fsi_daisy_epwmsync_node, the frame tag and frame type is configured by Slave MCU before receiving the ping packet, and the slave MCU need not change it. As a result, FSI can start sending the ping packet immediately when receiving the ping packet without involvement of the CPU, to implement Event Synchronization.

In their application, the ping/error/data frame are all needed to deliver among Master MCU and Slave MCU, Moreover, the Slave MCU changes the received data frame and then sent it out to next MCU. And the TX frame tage/type and buffer, etc, cannot be configured in advance. Therefore, there is unfix duration between MCU receiving and sending. In this situation, what is the solution to synchronize the event?

Thanks in advance.

Art

  • 0
    TI__Mastermind 45606 points

    Hi Art,

    Is your customer wanting to use the data frame for the event synchronization purpose instead of a ping frame? Periodic Ping frames are used in the example solution since they are the shortest possible FSI frame (i.e. will have the lowest latency). Any reason they can't use periodic ping frames in the background just for the event sync purpose?

    Best,

    Kevin

  • 0 in reply to Kevin Allen18
    TI__Genius 16795 points

    Hi Kevin,

    Thanks for the prompt response. I'll relay this to the customer and inform you as soon as I got their feedback.

    Cordially,

    Art

  • 0 in reply to Art Mecina
    TI__Mastermind 45606 points

    Hi Art,

    Great, please let me know what you learn.

    Thanks,

    Kevin

  • 0 in reply to Kevin Allen18
    TI__Genius 16795 points

    Hi Kevin,

    Good day.

    Below are the response from the customer in verbatim:

    "I want to use the data frame while synchronizing the event. The example project directly send the ping frame after receiving it without latency for running ISR. If I want slave MCU to change the received frame data through ISR and then send it to next MCU, there is latency, which affect the event synchronization, due to running the ISR to change the data frame and to configure the related registers.

    I read 《TMS320F2838x Microcontrollers TRM (Rev. B)》and note that an FSI transmitter module can be used in TDM mode as shown in Figure 32-12. It means that the “sync” frame for synchronizing event received from TDM input TDM input can be sent out to next slave MCU without latency, which similar to the example project, and the data frame received from FSI RX can be changed by ISR and then sent out. This solution meets my need.

     However, the FSI of TMS320F280049C does not have the TDM mode. Can aforementioned function be implemented through software with TMS320F280049C?"

    Thanks an regards,

    Art

  • 0 in reply to Art Mecina
    TI__Mastermind 45606 points

    Hi Art,

    Art Mecina said:
    I read 《TMS320F2838x Microcontrollers TRM (Rev. B)》and note that an FSI transmitter module can be used in TDM mode as shown in Figure 32-12. It means that the “sync” frame for synchronizing event received from TDM input TDM input can be sent out to next slave MCU without latency, which similar to the example project, and the data frame received from FSI RX can be changed by ISR and then sent out. This solution meets my need.

    This is correct, however please note that the TDM path in C2000 devices is a passive connection through the device. The FSI frame does not get re-transmitted so signal integrity / distortion can be a concern, especially if connecting many devices using TDM mode together.

    Art Mecina said:
     However, the FSI of TMS320F280049C does not have the TDM mode. Can aforementioned function be implemented through software with TMS320F280049C?"

    No, it cannot be implemented through software. Re-transmission would be required.

    Best,

    Kevin