MSP430F413: Msp430F413 every time the frequency is sometimes different

Hi,

could you please specify which clock frequency seems to be different? How did you perceive this, during debug or do you have extra code to measure time intervals for example by using a Timer to capture the time interval?

I'd suggest you to have a look at the Software Coding Techniques for MSP430 MCUs Application Report to get some guidance on the suggested code flow on MSP430 MCUs.

I noted that you're conducting some register settings inside the interrupt service routine and I'd suggest for you ta start looking into this to see if you could restructure your code -  you'll find guidance for that in the Application Report. Please also take a look at your WDTCTL settings. Currently, your interrupt service routine shows your repeating the register settings. As far as I see your not changing the seetings done in main, so those are not needed and might only generate overhead.

Please let me know if any of this helped you and please let me know how you tested and verified the different frequencies.

Best regards,

Britta

I changed the equivalent crystal oscillator, and it's the same phenomenon

hi,

a buzzer signal program output( BeePDeed (); ), the voice is not the same, oscilloscope detection frequency output is not the same.

my program is modified under the fet410_wdt_02 sample of MSP430x41x， fet410_wdt_02 sample to See the following. my program framework is the same as this sample。Fet410_wdt_02 sample, Can I modify the application directly？

         My program framework Description: using WDT configured for Interval Timer mode， Every 250ms detect of IO port  based on 32kHz ACLK WDT clock source.      ACLK = LFXT1 = 32768Hz, MCLK = SMCLK = default DCO = 32 x ACLK = 1048576Hz..

Next week, we need to deliver product samples to customers, do not know how to deal with it, and help modify the procedural framework.

  thank you!

PS:1、 fet410_wdt_02 sample  Demo - WDT, See the following ， 

      2、 My program framework sees the first PS program code。

//******************************************************************************
// MSP-FET430P410 Demo - WDT, Toggle P5.1, Interval Overflow ISR, 32kHz ACLK
//
// Description: Toggle P5.1 using WDT configured for Interval Timer mode.
// Interrupt toggles LED every 250ms based on 32kHz ACLK WDT clock source.
// ACLK = LFXT1 = 32768Hz, MCLK = SMCLK = default DCO = 32 x ACLK = 1048576Hz
// //* An external watch crystal between XIN & XOUT is required for ACLK *//
//
// MSP430F413
// -----------------
// /|\| XIN|-
// | | | 32kHz
// --|RST XOUT|-
// | |
// | P5.1|-->LED
//
// M. Buccini
// Texas Instruments Inc.
// Feb 2005
// Built with CCE Version: 3.2.0 and IAR Embedded Workbench Version: 3.21A
//*****************************************************************************
#include <msp430.h>

int main(void)
{
WDTCTL = WDT_ADLY_250; // WDT 250ms, ACLK, interval timer
FLL_CTL0 |= XCAP14PF; // Configure load caps
IE1 |= WDTIE; // Enable WDT interrupt
P5DIR |= 0x02; // Set P5.1 to output direction

__bis_SR_register(LPM3_bits + GIE); // Enter LPM3 w/interrupt
}

// Watchdog Timer interrupt service routine
#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
#pragma vector=WDT_VECTOR
__interrupt void watchdog_timer(void)
#elif defined(__GNUC__)
void __attribute__ ((interrupt(WDT_VECTOR))) watchdog_timer (void)
#else
#error Compiler not supported!
#endif
{
P5OUT ^= 0x02; // Toggle P5.1 using exclusive-OR
}