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TMS320F28374S: Tms320f28374s startup abnormal

Part Number: TMS320F28374S

Dear Expert

Sorry to reply late,the original question is https://e2e.ti.com/support/microcontrollers/c2000-microcontrollers-group/c2000/f/c2000-microcontrollers-forum/1105330/tms320f28374s-tms320f28374s-startup-abnormal-problem-analysis-report?tisearch=e2e-sitesearch&keymatch=%20user%3A470630#

Problem description

1.Rf project 10 test debugging discovery part of the module dc control board DSP startup time is different, the individual module starts the charge of the power and then rereturns the electricity, and the long time DSP is required to work.

Second, problem analysis

To solve the problem of DSP startup, the project team analyzes the three sides:

1.The external crystal oscillator of the signal;

In contrast to the normal start and abnormal launch of the DSP external crystal oscillator output, the output of the crystal oscillator is not different

2.The electric sequence of the DSP on the DSP;

The electrical sequence on DSP is shown in figure 2. The # 1 channel is 3.3vc, # 2 channel for 1.2vc, # 3 channel as the vibration output. The time sequence is the external set 3.3v first power, the kernel 1.2v after the power, compared different modules, the time of the time is consistent, there is no significant difference.

The DSP reset signal sequence is shown in figure 3. The # 2 channel is the reset signal, the # 3 channel for the kernel 1.2v power supply signal. The reset signal is high when the electricity is about 136ms on 1.2v. Compare different difference modules, the reset signal is not different.

And this is the  20220720 reply:

 1、Are you saying the startup time is different for multiple power-ups on the same board or are you saying the startup time is different across two (or more) boards, even though the design is identical?

 

    A:The startup time is different for multiple power-ups on the same board.

 

    2、Even though the above 3 points are true, there is still a difference in startup times. Is this correct?

 

    A:YES.

  • I am not clear on how you measure the startup time. Please clarify. Provide clear oscilloscope captures and clearly explain which signal is used to measure this and how is that signal generated.

  • Dear Hareesh

    Per customer said they measure the startup time through  obeserve a LED drvier by GPIO.

    1. Could you please provide a scope capture that clearly shows the following four signals: 3.3v, 1.2v, -XRS, GPIO? Please ensure that the 4 channels do not overlap each other and image resolution is good.
    2. What is the maximum deviation seen, in terms of when the GPIO pin is toggled with respect to -XRS going inactive?
  • Dear Hareeesh

    Normal

    CH1:3.3V;CH2:1.2V;CH3:GPIO;CH4:XRS

    Abnormal :CH1:3.3V;CH2:1.2V;CH3:GPIO;CH4:XRS;

    You can see that red line togging is slowly .

     

    1. The startup time of 28374 chip is slow. The normal startup time is 3-5 seconds, and the slow startup takes 1-3 minutes.

    2. The slow chip can be started normally after blowing the DSP slightly with the heat gun, but it cannot be started after 5 minutes.

  • The image quality of the scope screenshots is very poor. I have a hard time reading them. 

    You say Ch4 is -XRS. I can see that the vertical scale is 1v/division, but it doesn’t appear the pin rises to 3.3v when inactive. It could be that you are using a 10x probe.

    The normal startup time is 3-5 seconds, and the slow startup takes 1-3 minutes.

    These are not realistic start-up times at all. 

    It appears there is some hardware issue on your board. I am sorry I cannot help you on this.