Part Number: MSP430FR2355
Hi,
I am trying some stuff using MSP430FR2355 development board.. I am trying to get 1 ms timer Interrupt but not able to find the count value.
how do I calculated the 1 ms counter value.
Here is my clock setup.
[code]
#include <driverlib.h>
#include <strings.h>
#define MCLK_FREQ_MHZ 16 // MCLK = 16MHz
void Software_Trim() {
unsigned int oldDcoTap = 0xffff;
unsigned int newDcoTap = 0xffff;
unsigned int newDcoDelta = 0xffff;
unsigned int bestDcoDelta = 0xffff;
unsigned int csCtl0Copy = 0;
unsigned int csCtl1Copy = 0;
unsigned int csCtl0Read = 0;
unsigned int csCtl1Read = 0;
unsigned int dcoFreqTrim = 3;
unsigned char endLoop = 0;
do {
CSCTL0 = 0x100; // DCO Tap = 256
do {
CSCTL7 &= ~DCOFFG; // Clear DCO fault flag
}
while (CSCTL7 & DCOFFG); // Test DCO fault flag
__delay_cycles((unsigned int) 3000 * MCLK_FREQ_MHZ); // Wait FLL lock status (FLLUNLOCK) to be stable
// Suggest to wait 24 cycles of divided FLL reference clock
while ((CSCTL7 & (FLLUNLOCK0 | FLLUNLOCK1)) && ((CSCTL7 & DCOFFG) == 0))
;
csCtl0Read = CSCTL0; // Read CSCTL0
csCtl1Read = CSCTL1; // Read CSCTL1
oldDcoTap = newDcoTap; // Record DCOTAP value of last time
newDcoTap = csCtl0Read & 0x01ff; // Get DCOTAP value of this time
dcoFreqTrim = (csCtl1Read & 0x0070) >> 4; // Get DCOFTRIM value
if (newDcoTap < 256) // DCOTAP < 256
{
newDcoDelta = 256 - newDcoTap; // Delta value between DCPTAP and 256
if ((oldDcoTap != 0xffff) && (oldDcoTap >= 256)) // DCOTAP cross 256
endLoop = 1; // Stop while loop
else {
dcoFreqTrim--;
CSCTL1 = (csCtl1Read & (~DCOFTRIM)) | (dcoFreqTrim << 4);
}
}
else // DCOTAP >= 256
{
newDcoDelta = newDcoTap - 256; // Delta value between DCPTAP and 256
if (oldDcoTap < 256) // DCOTAP cross 256
endLoop = 1; // Stop while loop
else {
dcoFreqTrim++;
CSCTL1 = (csCtl1Read & (~DCOFTRIM)) | (dcoFreqTrim << 4);
}
}
if (newDcoDelta < bestDcoDelta) // Record DCOTAP closest to 256
{
csCtl0Copy = csCtl0Read;
csCtl1Copy = csCtl1Read;
bestDcoDelta = newDcoDelta;
}
}
while (endLoop == 0); // Poll until endLoop == 1
CSCTL0 = csCtl0Copy; // Reload locked DCOTAP
CSCTL1 = csCtl1Copy; // Reload locked DCOFTRIM
while (CSCTL7 & (FLLUNLOCK0 | FLLUNLOCK1))
; // Poll until FLL is locked
}
void init_CS(void) {
// Configure one FRAM waitstate as required by the device datasheet for MCLK
// operation beyond 8MHz _before_ configuring the clock system.
FRCTL0 = FRCTLPW | NWAITS_1;
__bis_SR_register(SCG0); // disable FLL
CSCTL3 |= SELREF__REFOCLK; // Set REFO as FLL reference source
CSCTL1 = DCOFTRIMEN_1 | DCOFTRIM0 | DCOFTRIM1 | DCORSEL_5; // DCOFTRIM=5, DCO Range = 16MHz
CSCTL2 = FLLD_0 + 487; // DCOCLKDIV = 16MHz
__delay_cycles(3);
__bic_SR_register(SCG0); // enable FLL
Software_Trim(); // Software Trim to get the best DCOFTRIM value
CSCTL4 = SELMS__DCOCLKDIV | SELA__REFOCLK; // set default REFO(~32768Hz) as ACLK source, ACLK = 32768Hz
// default DCOCLKDIV as MCLK and SMCLK source
}
void timer_b(void) {
Timer_B_initContinuousModeParam param = { 0 };
param.clockSource = TIMER_B_CLOCKSOURCE_SMCLK;
param.clockSourceDivider = TIMER_B_CLOCKSOURCE_DIVIDER_8;
param.timerInterruptEnable_TBIE = TIMER_B_TBIE_INTERRUPT_ENABLE;
param.startTimer = true;
param.timerClear = TIMER_B_SKIP_CLEAR;
Timer_B_initContinuousMode(TIMER_B1_BASE, ¶m);
}
int main(void) {
WDT_A_hold(WDT_A_BASE);
init_CS();
timer_b();
// Configure GPIO
P1DIR |= BIT0; // Set Pin as output
P1OUT |= BIT0;
PM5CTL0 &= ~LOCKLPM5;
__bis_SR_register(LPM3_bits | GIE); // Enter LPM3, interrupts enabled
__no_operation(); // For debugger
while (1) {
}
}
//******************************************************************************
//
//This is the Timer B0 interrupt vector service routine.
//
//******************************************************************************
#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
#pragma vector=TIMER0_B0_VECTOR
__interrupt
#elif defined(__GNUC__)
__attribute__((interrupt(TIMER0_B0_VECTOR)))
#endif
void TIMER0_B0_ISR(void) {
P1OUT ^= BIT0;
}
[/code]
