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Trouble getting my MSP430F2617 to work with an external 16 MHz oscillator

Other Parts Discussed in Thread: MSP430F2617, MSP430WARE

I'm still having trouble getting my MSP430F2617 to work with an external 16 MHz oscillator. Thanks for the earlier comments. The MSP430F261x and 241x data sheet(SLAS541K)  indicate the ability to use an external oscillator. Does anyone have sample code

The processor is an 80 pin  MSP430F2617 

The following is sample code that produces 16MHz on SMCLK (pin49) and 112KHz on MCLK (pin48)

int main(void)
{
static int i, j, k, n, dac;

WDTCTL = WDTPW | WDTHOLD; // Stop watchdog timer

// set master clock to external 16.000 MHz oscillator
P8DIR = 0x00; // P8.7 is the 16.00 MHz osc input
P8SEL |= 0x80; // ditto

BCSCTL1 = 0xc0; // XT2 is used for MCLK
BCSCTL3 = 0xf0;

for ( i = 0; i < 5000; i++ );  // short delay

BCSCTL2 = 0x88; // use XT2 clock
......
}

  • Hi Raymond,

    I found the "MSP430x261x_hfxt2.c" code example in MSP430Ware in CCS. This reference combined with the datasheet and User's Guide should get you started.

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    //******************************************************************************
    //  MSP430x26x Demo - Basic Clock, MCLK Configured to Operate from XT2 HF XTAL
    //
    //  Description: Proper selection of an external HF XTAL for MCLK is shown
    //  using HF XT2 OSC. OFIFG is polled until the HF XTAL is stable; only then is 
    //  MCLK sourced by XT2.  MCLK is buffered on P5.4 and MCLK/10 is on P1.1 driven 
    //  by a software loop taking exactly 10 CPU cycles.
    //  ACLK = MCLK = LFXT1 = HF XTAL, SMCLK = default DCO ~1.045MHz
    //  //* XT2 HF XTAL NOT INSTALLED ON FET *//
    //  //* Min Vcc required varies with MCLK frequency - refer to datasheet *//
    //
    //              MSP430F261x/241x
    //             -----------------
    //         /|\|              XIN|-
    //          | |                 |
    //          --|RST          XOUT|-
    //            |                 |
    //            |                 |
    //            |            XT2IN|-
    //            |                 | HF XTAL (400kHz - 16MHz)
    //            |           XT2OUT|-
    //            |                 |
    //            |             P1.1|-->MCLK/10 = XT2 HFXTAL/10
    //            |        P5.4/MCLK|-->MCLK = XT2 HFXTAL
    //
    //  B. Nisarga
    //  Texas Instruments Inc.
    //  September 2007
    //  Built with CCE Version: 3.2.0 and IAR Embedded Workbench Version: 3.42A
    //******************************************************************************
    #include <msp430.h>
    
    volatile unsigned int i;
    
    int main(void)
    {
      WDTCTL = WDTPW + WDTHOLD;                 // Stop WDT
    
      P5DIR |= 0x10;                            // P5.4= output direction
      P5SEL |= 0x10;                            // P5.4= MCLK option select
      P1DIR |= 0x02;                            // P1.1 = output direction
    
      BCSCTL1 &= ~XT2OFF;                       // Activate XT2 high freq xtal
      BCSCTL3 |= XT2S_2;                        // 3 – 16MHz crystal or resonator
    
      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_2;                        // MCLK = XT2 HF XTAL (safe)
    
      for (;;)                                  // Infinite loop
      {
        P1OUT |= 0x02;                          // P1.1 = 1
        P1OUT &= ~0x02;                         // P1.1 = 0
      }
    }
    

    Here's a screenshot of the XT2 section in the datasheet.

    Regards,

    James

    MSP Customer Applications

  • You said: "The MSP430F261x and 241x data sheet(SLAS541K) indicate the ability to use an external oscillator."
    I did not see that at all.
  • No matter which package type of this chip you use, there is no external oscillator clock input pin.
  • old_cow_yellow said:
    No matter which package type of this chip you use, there is no external oscillator clock input pin.

    Sure? All packages have XT2IN that can be configured to work with an external clock source by setting XT2S_3 in BCSCTL3, I think.

    Dennis

  • Dennis,

    You are right.  I missed that. Thanks.

    Raymond

    I was incorrect. See SLAU144.pdf, 2nd paragraph of Section 5.2.4  XT2 Oscillator.

    --OCY

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