Detecting the reset source on the TMS320F2808


I'd like to know if it's possible to detect the reset source on the TMS320F2808 DSP Controller. I read a documment (spra356a) showing it's possible for the TMS320x240, but i didn't find anything talking about the F2808. If it's not a internal way to do this, could someone give me a suggestion to detect it with some external components?


Thank you.

3 Replies

  • Hatus,


    We have resolved this through the support channel but I will post the answer here for everyone else to view as well:


    There are three sources of reset for the F280x devices: External, Watchdog, and Clock Failure. There are status bits to specify which source caused this within the device but externally they all cause the RS line to be pulled low. The status bits for the Watchdog and Clock Failure source shown in the clocking section of the System Control and Reference Guide:



    The Oscillator fault is discussed in section 3.2.2 and the Watchdog is discussed in 3.4.




    Tim Love


  • In reply to Tim Love:

    Hello Tim,

       Thank you for your answer, but I still have one problem to need your help.

      I encountered one problem that my DSP reset about every 7ms, and I am not sure which factor caused it.

    Fig.1 Reset circuit

    MAX706R3V Voltage Monitoring, Low-Cost Supervisory Circuits;

    D55MMBD700LT1,Dual Switching Diode;

    R288c102 composed RC charge circuit for 510ms delay;

    RESET_DSP connect to XRS pin of DSP F2808.


    Test wave:

    CH1(Y)-signal of D55 Pin1, RC charging_discharging signal;

    CH2(R)-signal of D55 Pin2, the output of MAX706R;

    CH3(B)- signal of D55 Pin3, the reset signal of DSP.

    Fig.2 Test wave of after DSP flashed to debug


    Fig.3 Test wave of after reset the power

      You can see the circuit and test wave above.For fig.2, It is the test wave after I flash the DSP. Then I disconnected the DSP with flasher, turned off  the power and turned it on again, I found the wave of fig.3 that DSP reseted continually and RC circuit can`t charge to high level voltage.And each time I reset the power after that, the wave is so the same.I am not sure whether the RESET signal is output or input of DSP.And I don`t know which cause it, as I had disableed the WDG and tested the Oscillator is normal. Even I conneteted the pin2 and pin3 of D55 with lead directly, the DSP also reset every 7ms. Could you please analyse it for me? Thanks


    Jason Fu

  • In reply to Tim Love:


    Complement the circuit and test wave.6278.RESET.doc