Problem Setting Timer Interrupt 1 Mhz on MSP430FR6989LP

[Lukman 1]

Hi Guys,

I just writing code using Energia format on CCS 8. I want to set the timer Interrupt on 1 Mhz frequency.
But as I check using Osiloscope, it just shown 53.8 Khz. Please kindly advise to fix my code as below.

 

I appreciate your help.

Regards,

Lukman

 

 

#include <msp430.h>
const int ledPin2 = 39;

void setup()
{
// put your setup code here, to run once:
pinMode(ledPin2,OUTPUT);
setupTimer(1); // set timer period to 1000 micro seconds
}

void loop()
{

}

void OnTimer()
{
static int msCount=0;
static int state=0; // Remember LED state for toggling purposes

msCount++;
if (msCount >=1)//// Count 1000 milliseconds to allow a 1 second pulse
{ 
msCount = 0;
digitalWrite(ledPin2,state); // Write to Green LED
state=~state; // toggle state 
}

}

void setupTimer(unsigned Period)
{
WDTCTL = WDTPW | WDTHOLD; // Stop WDT

// Configure one FRAM waitstate as required by the device datasheet for MCLK
// operation beyond 8MHz _before_ configuring the clock system.
FRCTL0 = FRCTLPW | NWAITS_1;

// Clock System Setup
CSCTL0_H = CSKEY >> 8; // Unlock CS registers
CSCTL1 = DCOFSEL_4 | DCORSEL; // Set DCO to 16MHz
CSCTL2 = SELA__VLOCLK | SELS__DCOCLK | SELM__DCOCLK; // Set SMCLK = MCLK = DCO,
// ACLK = VLOCLK
CSCTL3 = DIVA__1 | DIVS__1 | DIVM__1; // Set all dividers
CSCTL0_H = 0; // Lock CS registers

// Configuration word
// Bits 15-10: Unused
// Bits 9-8: Clock source select: set to SMCLK (16MHz)
// Bits 7-6: Input divider: set to 8
// Bits 5-4: Mode control: Count up to TACCRO and reset
// Bit 3: Unused
// Bits 2: TA0CLR : set to initially clear timer system
// Bit 1: Enable interrupts from TA0
// Bit 0: Interrupt (pending) flag : set to zero (initially)
//TA0CTL=0b0000001001010010;// Bits 7-6: Input divider: set to 8
TA0CTL=0b0000001000010110;// Bits 7-6: Input divider: set to 1
TA0CCR0=Period*1; 
TA0CCTL0=BIT4; // Enable interrupts when TAR = TACCR0

}

// The address function that follows this vector statement is placed in the specified location Interrupt Vector table 
#pragma vector=TIMER0_A0_VECTOR
__interrupt void timerA0ISR(void)
{
// Timer A0 Interrupt service routine
OnTimer();
TA0CTL &= ~BIT0; // Acknowledge the interrupt

}