timestamp_t lp_ticker_read()
{
if (! lp_ticker_inited) {
lp_ticker_init();
}
TIMER_T * timer2_base = (TIMER_T *) NU_MODBASE(timer2_modinit.modname);
do {
uint64_t major_minor_clks;
uint32_t minor_clks;
// NOTE: As TIMER_CNT = TIMER_CMP and counter_major has increased by one, TIMER_CNT doesn't change to 0 for one tick time.
// NOTE: As TIMER_CNT = TIMER_CMP or TIMER_CNT = 0, counter_major (ISR) may not sync with TIMER_CNT. So skip and fetch stable one at the cost of 1 clock delay on this read.
do {
core_util_critical_section_enter();
// NOTE: Order of reading minor_us/carry here is significant.
minor_clks = TIMER_GetCounter(timer2_base);
uint32_t carry = (timer2_base->INTSTS & TIMER_INTSTS_TIF_Msk) ? 1 : 0;
// When TIMER_CNT approaches TIMER_CMP and will wrap soon, we may get carry but TIMER_CNT not wrapped. Handle carefully carry == 1 && TIMER_CNT is near TIMER_CMP.
if (carry && minor_clks > (TMR2_CLK_PER_TMR2_INT / 2)) {
major_minor_clks = (counter_major + 1) * TMR2_CLK_PER_TMR2_INT;
} else {
major_minor_clks = (counter_major + carry) * TMR2_CLK_PER_TMR2_INT + minor_clks;
}
core_util_critical_section_exit();
} while (minor_clks == 0 || minor_clks == TMR2_CLK_PER_TMR2_INT);
// Add power-down compensation
return ((uint64_t) major_minor_clks * US_PER_SEC / TMR2_CLK_PER_SEC / US_PER_TICK);
} while (0);
}
void TMR1_IRQHandler(void)
{
// Timer clock is 1 MHz ( prescaler is set to 11 + 1), counter value records the duration for 1000 event counts.
printf("Event frequency is %d Hz\n", (1000000 * 1000) / TIMER_GetCounter(TIMER1));
TIMER_ClearCaptureIntFlag(TIMER1);
complete = 1;
}
uint32_t us_ticker_read()
{
if (! ticker_inited) {
us_ticker_init();
}
TIMER_T *timer_base = (TIMER_T *) NU_MODBASE(TIMER_MODINIT.modname);
return (TIMER_GetCounter(timer_base) / NU_TMRCLK_PER_TICK);
}
uint32_t lp_ticker_read()
{
if (! lp_ticker_inited) {
lp_ticker_init();
}
TIMER_T * timer2_base = (TIMER_T *) NU_MODBASE(timer2_modinit.modname);
do {
uint64_t major_minor_ms;
uint32_t minor_ms;
// NOTE: As TIMER_CNT = TIMER_CMP and counter_major has increased by one, TIMER_CNT doesn't change to 0 for one tick time.
// NOTE: As TIMER_CNT = TIMER_CMP or TIMER_CNT = 0, counter_major (ISR) may not sync with TIMER_CNT. So skip and fetch stable one at the cost of 1 clock delay on this read.
do {
uint32_t _state = __get_PRIMASK();
__disable_irq();
// NOTE: Order of reading minor_us/carry here is significant.
minor_ms = TIMER_GetCounter(timer2_base) * MS_PER_TMR2_CLK;
uint32_t carry = (timer2_base->INTSTS & TIMER_INTSTS_TIF_Msk) ? 1 : 0;
// When TIMER_CNT approaches TIMER_CMP and will wrap soon, we may get carry but TIMER_CNT not wrapped. Hanlde carefully carry == 1 && TIMER_CNT is near TIMER_CMP.
if (carry && minor_ms > (MS_PER_TMR2_INT / 2)) {
major_minor_ms = (counter_major + 1) * MS_PER_TMR2_INT;
}
else {
major_minor_ms = (counter_major + carry) * MS_PER_TMR2_INT + minor_ms;
}
__set_PRIMASK(_state);
}
while (minor_ms == 0 || minor_ms == MS_PER_TMR2_INT);
// Add power-down compensation
return (major_minor_ms / MS_PER_TICK);
}
while (0);
}
/*---------------------------------------------------------------------------------------------------------*/
int main(void)
{
volatile uint32_t u32InitCount;
/* Unlock protected registers */
SYS_UnlockReg();
/* Init System, peripheral clock and multi-function I/O */
SYS_Init();
/* Lock protected registers */
SYS_LockReg();
/* Init UART0 for printf */
UART0_Init();
printf("\n\nCPU @ %d Hz\n", SystemCoreClock);
printf("+-------------------------------------------------+\n");
printf("| Timer1 External Counter Input Sample Code |\n");
printf("+-------------------------------------------------+\n\n");
printf("# Timer Settings:\n");
printf(" Timer1: Clock source is HCLK(50 MHz); Continuous counting mode; Interrupt enable;\n");
printf(" External counter input enable; TCMP is 56789.\n");
printf("# Connect P2.0 to T1 pin and pull P2.0 High/Low as T1 counter input source.\n\n");
/* Configure P2.0 as GPIO output pin and pull pin status to Low first */
GPIO_SetMode(P2, 0, GPIO_PMD_OUTPUT);
P20 = 0;
/* Initial Timer1 default setting */
TIMER_Open(TIMER1, TIMER_CONTINUOUS_MODE, 1);
/* Configure Timer1 setting for external counter input function */
TIMER_SELECT_TOUT_PIN(TIMER1, TIMER_TOUT_PIN_FROM_TX_PIN);
TIMER_SET_PRESCALE_VALUE(TIMER1, 0);
TIMER_SET_CMP_VALUE(TIMER1, 56789);
TIMER_EnableEventCounter(TIMER1, TIMER_COUNTER_FALLING_EDGE);
TIMER_EnableInt(TIMER1);
/* Enable Timer1 NVIC */
NVIC_EnableIRQ(TMR1_IRQn);
/* Clear Timer1 interrupt counts to 0 */
g_au32TMRINTCount[1] = 0;
/* Start Timer1 counting */
TIMER_Start(TIMER1);
/* To check if TDR of Timer1 must be 0 as default value */
if(TIMER_GetCounter(TIMER1) != 0)
{
printf("Default counter value is not 0. (%d)\n", TIMER_GetCounter(TIMER1));
/* Stop Timer1 counting */
TIMER_Close(TIMER1);
while(1);
}
/* To generate one counter event to T1 pin */
GeneratePORT2Counter(0, 1);
/* To check if TDR of Timer1 must be 1 */
while(TIMER_GetCounter(TIMER1) == 0);
if(TIMER_GetCounter(TIMER1) != 1)
{
printf("Get unexpected counter value. (%d)\n", TIMER_GetCounter(TIMER1));
/* Stop Timer1 counting */
TIMER_Close(TIMER1);
while(1);
}
/* To generate remains counts to T1 pin */
GeneratePORT2Counter(0, (56789 - 1));
while(1)
{
if((g_au32TMRINTCount[1] == 1) && (TIMER_GetCounter(TIMER1) == 56789))
{
printf("Timer1 external counter input function ... PASS.\n");
break;
}
}
/* Stop Timer1 counting */
TIMER_Close(TIMER1);
while(1);
}
/*---------------------------------------------------------------------------------------------------------*/
int main(void)
{
volatile uint32_t u32InitCount;
/* Unlock protected registers */
SYS_UnlockReg();
/* Init System, peripheral clock and multi-function I/O */
SYS_Init();
/* Lock protected registers */
SYS_LockReg();
/* Init UART0 for printf */
UART0_Init();
printf("\n\nCPU @ %d Hz\n", SystemCoreClock);
printf("+-------------------------------------------------+\n");
printf("| Timer1 External Counter Input Sample Code |\n");
printf("+-------------------------------------------------+\n\n");
printf("# Timer Settings:\n");
printf(" Timer1: Clock source is HCLK(50 MHz); Continuous counting mode; Interrupt enable;\n");
printf(" External counter input enable; TCMP is 56789.\n");
printf("# Connect P2.0 to T1 pin and pull P2.0 High/Low as T1 counter input source.\n\n");
/* Configure P2.0 as GPIO output pin and pull pin status to Low first */
P2->PMD = 0xFFFD;
P20 = 0;
/* Enable Timer1 NVIC */
NVIC_EnableIRQ(TMR1_IRQn);
/* Clear Timer1 interrupt counts to 0 */
g_au32TMRINTCount[1] = 0;
/* Enable Timer1 external counter input function */
TIMER1->TCMPR = 56789;
TIMER1->TCSR = TIMER_TCSR_CEN_Msk | TIMER_TCSR_IE_Msk | TIMER_TCSR_CTB_Msk | TIMER_CONTINUOUS_MODE;
/* To check if TDR of Timer1 must be 0 as default value */
if(TIMER_GetCounter(TIMER1) != 0)
{
printf("Default counter value is not 0. (%d)\n", TIMER_GetCounter(TIMER1));
/* Stop Timer1 counting */
TIMER1->TCSR = 0;
while(1);
}
/* To generate one counter event to T1 pin */
GeneratePORT2Counter(0, 1);
/* To check if TDR of Timer1 must be 1 */
while(TIMER_GetCounter(TIMER1) == 0);
if(TIMER_GetCounter(TIMER1) != 1)
{
printf("Get unexpected counter value. (%d)\n", TIMER_GetCounter(TIMER1));
/* Stop Timer1 counting */
TIMER1->TCSR = 0;
while(1);
}
/* To generate remains counts to T1 pin */
GeneratePORT2Counter(0, (56789 - 1));
while(1)
{
if((g_au32TMRINTCount[1] == 1) && (TIMER_GetCounter(TIMER1) == 56789))
{
printf("Timer1 external counter input function ... PASS.\n");
break;
}
}
/* Stop Timer1 counting */
TIMER1->TCSR = 0;
while(1);
}
