static void timer2_setup ( void ) {
//timer_reset ( TIM2 );
//timer_set_mode
//timer_continuous_mode ( TIM2 );
/* Set timer start value. */
TIM_CNT(TIM2) = 1;
/* Set timer prescaler. 72MHz/1440 => 50000 counts per second. */
TIM_PSC(TIM2) = 300; // 280K/s or 0.000 003 571
/* End timer value. If this is reached an interrupt is generated. */
TIM_ARR(TIM2) = 8; //
// o-scope reports:
// prescale 2000, 1->600 should be 100/sec; in fact, we're exactly 20ms between which is exactly 50 .. so callback is 60MHz, not 120MHz
// manual says:
// The reference manual (see page 133) states that the GPIO is capable of:
// Fast toggle capable of changing every two clock cycles
// --> okay so at 120MHz, the best we can do is 60MHz of GPIO. But thats different than here, where the timer seems halved..
/* Update interrupt enable. */
TIM_DIER(TIM2) |= TIM_DIER_UIE;
//timer_set_repetition_counter ( TIM2, 100 );
/* Start timer. */
TIM_CR1(TIM2) |= TIM_CR1_CEN;
return;
}
int main(void)
{
rcc_clock_setup_in_hse_16mhz_out_72mhz();
gpio_setup();
nvic_setup();
gpio_clear(GPIOB, GPIO7); /* LED1 on */
gpio_set(GPIOB, GPIO6); /* LED2 off */
rcc_peripheral_enable_clock(&RCC_APB1ENR, RCC_APB1ENR_TIM2EN);
/* the goal is to let the LED2 glow for a second and then be off for a second */
/* Set timer start value */
TIM_CNT(TIM2) = 1;
/* Set timer prescaler. 72MHz/1440 => 50000 counts per second */
TIM_PSC(TIM2) = 1440;
/* End timer value. If this value is reached an interrupt is generated */
TIM_ARR(TIM2) = 50000;
/* Update interrupt enable */
TIM_DIER(TIM2) |= TIM_DIER_UIE;
/* Start timer */
TIM_CR1(TIM2) |= TIM_CR1_CEN;
while(1); /* Halt. */
return 0;
}
bool timer_get_flag(u32 timer_peripheral, u32 flag)
{
if (((TIM_SR(timer_peripheral) & flag) != 0) &&
((TIM_DIER(timer_peripheral) & flag) != 0)) {
return true;
}
return false;
}
/**
* @brief Initializes the AEAT9000 SSI Link
* @param u16 clk_speed SSI Clock Speed in 100bps LSB units
*/
void ssi_initialize(u16 clk_speed)
{
rcc_peripheral_enable_clock(&RCC_APB1ENR, RCC_APB1ENR_TIM2EN); // Initialize timer clk
// Initialize I/O Pins
gpio_set_mode(SSI_GPIO, GPIO_MODE_OUTPUT_10_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, SSI_CLK_PIN);
gpio_set_mode(SSI_GPIO, GPIO_MODE_INPUT, GPIO_CNF_INPUT_PULL_UPDOWN, SSI_DATA_PIN);
gpio_set_mode(SSI_GPIO, GPIO_MODE_OUTPUT_10_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, SSI_NCS_PIN);
// Initialize clock timer on TIM1
TIM_DIER(SSI_TIMER) = TIM_DIER_UIE;
TIM_PSC(SSI_TIMER) = 1; // 24MHz Clock
TIM_ARR(SSI_TIMER) = TIMER_MAX; // Update at 500kHz
// Initialize NVIC
nvic_enable_irq(NVIC_TIM2_IRQ);
nvic_set_priority(NVIC_TIM2_IRQ, 1);
ssi_state = SSI_IDLE;
ssi_data_ready_flag = false;
}
void timer_enable_irq(u32 timer_peripheral, u32 irq)
{
TIM_DIER(timer_peripheral) |= irq;
}
void timer_disable_irq(u32 timer_peripheral, u32 irq)
{
TIM_DIER(timer_peripheral) &= ~irq;
}
