• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 79 subscribers
  • Views 666 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

MSP430F5529 - Different Response Times in Debug Mode than Off Debug Mode

Rodney Wong
Intellectual 650 points
Other Parts Discussed in Thread: MSP430F5529

I just noticed that when I go off of debug mode the response time of the MSP430F5529 changes. 

The 5529 is initialized with the DCO clocking the clocks at 25MHz. Then the 5529 waits for interrupts on PORT1. When the 5529 is in debug mode, the response to the interrupt is about 0.72us. When the 5529 is not in debug mode, the response is about 135us.

What's going on? Does debug mode setup the 5529 in a certain way?

P.S. The 5529 is on a LaunchPad. So could the FET be doing something?

  • 0
    Intellectual 650 points
    I was doing some tests. I found that this response difference is caused by the MCU being in LPM. I suppose the MCU is in a different LPM mode in debug vs offline.
  • 0 in reply to Rodney Wong
    TI__Guru* 77761 points
    Rodney,

    Your hypothesis about LPM is exactly right - basically, the debugger has to keep the power management module in a certain state so that it can maintain control and access that part. So when you are in debug mode, the part can't truly go as deep asleep as it would for some of the lower power modes - this also means a shorter wakeup time. So for timing-related things or power-related things with deep LPMs, it would be recommended to run your tests stand-alone. Or while in a debug session in CCS, you could try selecting Run > Free Run to have it fully release the part to run without debugger.

    Regards,
    Katie

**Attention** This is a public forum