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c6678 network problem

feng
Intellectual 270 points

Hello,

1. I measured hua demo of 6678 transmission speed as follows:

 

But only 8MB/s measured using the software on a PC, what is the reason for it?

2.When my program using NDK on C6678,  what is the maxed speed can the network reach?

can anyone help me ?

Thanks!

  • 0
    TI__Guru* 95265 points

    Weifeng,

    This is UDP or TCP test? What is the software you used on PC to measure the throughput? Can you do a Wireshark capture, then you will see the actual time spent for the given amount of packets transmitted. That can be used to calculate throughput.

    Regards, Eric

      

  • 0 in reply to lding
    TI__Guru* 95265 points

    Weifeng,

    One thing to note if you use Wireshark to calculate the throughput: the Wireshark may not capture all the packets at such high rate. However you can look at the IP header identification field to count how many packets Tx/Rx, this field is 16-bit, so need to consider the wrap-around.   

    Regards, Eric

  • 0 in reply to lding
    Intellectual 270 points

    Iding,

        Thank you very much for your attention. Actually, I have tried another approach. I wrote a small software using MFC, which can communicate with C6678 based on TCP protocol. Then the software sent 100 pictures(each size is 2M byte) to DSP.The phenomenon is that the total time used by transmission is 19 seconds measured by the soft on PC .But the program running on DSP shows that the total time used on receiving is 2.8 seconds.  It should be noted that, the DSP program is downloaded through the emulator to the DSP and run in debug mode. So there is something wrong in the DSP program. Then i build a release version of the DSP program and programed it to

    the  NOR Flash. Make C6678 boot from the NOR, and again send100 pictures(each size is 2M byte) through the software on PC to the DSP. The  information on the HyperTerminal printed by DSP shows that the total time used by DSP to receive 100 pictures is 2.8 seconds.  The transmission time measured by the software on PC is 2.8 senconds too.

          So i think that the throughput can reach 70 MB/s using NDK (TCP protocol).  The performance of the program  may decrease when it runs in debug model with emulator.

          Am i right?

      Regards.

  • 0 in reply to feng
    TI__Guru* 95265 points

    Weifeng,

    The HUA demo should have the same throughput results no matter boot from NOR or using CCS to download.

                               PC              DSP

    CCS load:          19                2.8

    NOR:                  2.8              2.8

    With the discrepencies, why you think PC is correct, not DSP? The timing problem of DSP can come from PLL setting. In CCS load mode, I thought you must have run the GEL script to initialize the DSP, which includes PLL setting, otherwise DDR3 is not configured and you can't load the program and run. If GEL is run, the PLL should be correct (Note, if you do DSP system reset via CCS, you need to re-run GEL).

    Regards, Eric     

  • 0 in reply to lding
    Intellectual 270 points

    Iding,

         1. I can make sure that the PC is correct.

         2. Just as you mentioned I have run the GEL scirpt to intialize the DSP in CCS load mode.

         3. You said that the HUA demo should have the same throughput results no matter boot from NOR or using CCS to download.

             I think the information on the Web page is reported by DSP. We have no other means to make sure that weather the throughput on boot from NOR or using CCS to    download is same.   It should be noted that the DSP program  I used to measure the net throughput is my own program not the HUA demo. 

    As you can see, the DSP shows the time used on receiving is 2.8s in CCS load mode and the time used on receiving is also 2.8s when boot from NOR. But the  software on PC side shows that the time used on transmission is different when DSP program runs on differernt mode.

       When the DSP program runs with emulator, whether the emulator can suspend the DSP running ? In other words, whether the emulator will affect  DSP clock ticks?

    It seems that the time measure by DSP in CCS mode with emolator is not the same with the time in real world. It seems the time measured by DSP  is not the same with the time in real world. Such as when DSP shows the time is 2.8s (in CCS mode with emulator), actually the real time is 19s.

     

    Thank you!