• State
  • Locked Locked
  • Replies 2 replies
  • Subscribers 78 subscribers
  • Views 666 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

MSP430F2370 EXTERNAL CLOCK

ISTVAN MATE
Intellectual 260 points
Other Parts Discussed in Thread: MSP430F2370

I am trying to use a 16 MHz external clock on PIN 2 for the MSP430F2370 micro. Here is my init code:

// Set the 16 MHz oscillator as the input clock on XIN

BCSCTL1 &= ~(XT2OFF); // XT2 OSCILLATOR - clear the bit

BCSCTL1 |= XTS; // LFXT1 - High frequency mode

BCSCTL2 |= SELM_3 + SELS; // MCLK = LFXT1CLK, SCLK = LFXT1CLK,

BCSCTL3 = LFXT1S_3 + XCAP_0; // XT1 11 Digital external clock source on PIN 2

// SET PIN 8 AS SMCLK OUTPUT - P1.4

P1SEL |= 0x10; // SET primary peripheral function SMCK

P1DIR |= 0x10; // P1.4 output

 

I single step through the above code and I can see the BCSCTLx registers are set up according to the code above but I cannot see SMCLK on P1.4. I can see the 16 MHz clock on pin 2 as the input for XIN.

I am suspicious of MCLK running as well. I am using SPI to send some data and the SPI clock is missing. SPI is configured as master.

I am using CCSv5.

 

Can somebody help me figure out what is going on?

  • 0
    TI__Guru**** 202096 points

    Hello Istvan,

    Some quick notes on your initialization:

    1) BCSCTL1 &= ~(XT2OFF); is unnecessary since XT2 is not available on the MSP430F2370.

    2)  Set BCSCTL3 after BCSCTL1, check the OSCFault flag, and then set BCSCTL2, like so:

      BCSCTL1 |= XTS;                           // LFXT1 - High frequency mode
  BCSCTL3 |= LFXT1S_3 + XCAP_0;             // XT1 11 Digital external clock source on PIN 2

  do
  {
    IFG1 &= ~OFIFG;                         // Clear OSCFault flag
    for (i = 0xFF; i > 0; i--);             // Time for flag to set
  }
  while (IFG1 & OFIFG);                     // OSCFault flag still set?

  BCSCTL2 |= SELM_3 + SELS;                 // MCLK = LFXT1CLK, SCLK = LFXT1CLK,

    Otherwise your implementation seems correct.  You should definitely be able to see SMCLK on P1.4, not being able to indicates an oscillator fault condition.  Please make the changes I outlined and let me know if while in the debugger your code gets stuck on the OSCFault loop.

    Regards, Ryan

  • 0
    TI__Guru**** 202096 points
    Hi Istvan,

    Are you still having any problems with your external clock?

    Regards,
    Ryan

**Attention** This is a public forum