void generator_qenc_set_freq(uint32_t freq)
{
/* Number of ticks per step */
uint16_t ticks = 0;
/* The following code calculates the upper boundary of the timer and the
* interrupt positions to get a correct Quadrature signal of the given
* frequency.
* The different compare interrupts sets the phase0 and phase90 signals.
* Phase-0 uses Pin1, Phase90-Pin2 and Index-Pin3 from selected port
*
* Compare A interrupt clear phase0 and sets phase90
* Compare B interrupt sets phase0 and phase90
* Compare C interrupt sets phase0 and clear phase90
* Compare D interrupt clears phase0 and phase90.
*
* Compare A interrupt also sets the index signal when one round has
* passed.
*/
/* Calculates upper boundary of timer to get desired frequency */
tc_set_resolution(generator_qenc_timer,
(freq * generator_qenc_revolution) / 1000);
ticks = ((uint64_t)tc_get_resolution(generator_qenc_timer) *
1000) / (freq * generator_qenc_revolution);
/* Write timer period register */
tc_write_count(generator_qenc_timer, 0);
tc_write_period(generator_qenc_timer, ticks);
}
/**
* \brief Configure timer interrupts for touch measurements
*/
static void touch_init_timer_isr(void)
{
tc_enable(&TOUCH_TC);
tc_set_overflow_interrupt_callback(&TOUCH_TC, &touch_timer_period_handler);
tc_set_resolution(&TOUCH_TC, (uint32_t)1000000);
tc_write_period(&TOUCH_TC, (tc_get_resolution(&TOUCH_TC)
* TOUCH_TC_PERIOD_MS) / 1000);
tc_set_overflow_interrupt_level(&TOUCH_TC, TC_INT_LVL_LO);
}
/**
* \internal
* \brief Generate a delay in ms
*
* \param delay_ms Number of ms to wait
*/
static void main_delay_ms(uint16_t delay_ms)
{
uint16_t ticks_delay;
tc_write_count(CONF_DELAY_TC, 0);
ticks_delay = (uint64_t)tc_get_resolution(CONF_DELAY_TC) * delay_ms
/ 1000;
while (ticks_delay > tc_read_count(CONF_DELAY_TC)) {
}
}
void sha204_delay_us(uint16_t delay)
{
// Configure TC resolution and period (value at which overflow is triggered).
tc_set_resolution(DELAY_COUNTER, 1000000); // causes a divisor value of 8 => 250 ns for system clock = 32 MHz
// Get actual resolution.
uint32_t resolution = tc_get_resolution(DELAY_COUNTER);
// Write value for delay to counter register.
tc_write_period(DELAY_COUNTER, (resolution * (uint32_t) delay) / 1000000);
// Restart counter.
tc_restart(DELAY_COUNTER);
// Reset timeout flag.
sha204_timer_expired = false;
// Wait for timer to expire.
while (sha204_timer_expired == false);
}
/**
* \brief Get resolution in Hz for TC clock selection.
* \internal
*
* \param tc_id ID of TC.
* \param timer_res Clock selection for TC.
*
* \return TC resolution in Hz.
*/
uint32_t tc_timer_get_resolution(uint8_t tc_id, timer_res_t timer_res)
{
return tc_get_resolution(tc_id, timer_res);
}
static void qdec_enabled_tc_freq(qdec_config_t *config)
{
volatile uint8_t *evsys_chctrl, *evsys_chctrl_freq;
/* Configuration of frequency calculation */
Assert(config->event_channel != config->freq_opt.event_channel);
if (config->index.enabled) {
Assert((config->event_channel + 1)
!= config->freq_opt.event_channel);
}
#if XMEGA_E
/* Channel must be < 4, because QDec channel is 0
* and EVSYS.DFCTRL enables filter per event group */
Assert(config->freq_opt.event_channel < 4);
#endif
/* In event channel enable digital filter as QDec event channel */
#if XMEGA_E
if (EVSYS.DFCTRL & EVSYS_PRESCFILT_CH04_gc) {
if (config->freq_opt.event_channel == 1) {
EVSYS.DFCTRL |= EVSYS_PRESCFILT_CH15_gc;
} else if (config->freq_opt.event_channel == 2) {
EVSYS.DFCTRL |= EVSYS_PRESCFILT_CH26_gc;
} else {
EVSYS.DFCTRL |= EVSYS_PRESCFILT_CH37_gc;
}
}
#endif
evsys_chctrl_freq = &EVSYS.CH0CTRL + config->freq_opt.event_channel;
evsys_chctrl = &EVSYS.CH0CTRL + config->event_channel;
*evsys_chctrl_freq = *evsys_chctrl & EVSYS_DIGFILT_gm;
/* Configure event channel for frequency calculation */
qdec_evsys_pin_2_chmux(config->port, config->pins_base,
config->freq_opt.event_channel);
/* Configure TC to capture frequency
* Load timer period register
* Enable capture on CCA channel
* Select timer clock source
*/
tc_enable(config->freq_opt.timer);
tc_set_input_capture(config->freq_opt.timer,
(TC_EVSEL_t)(TC_EVSEL_CH0_gc
+ config->freq_opt.event_channel),
TC_EVACT_FRQ_gc);
tc_write_count(config->freq_opt.timer, 0);
tc_write_period(config->freq_opt.timer, 0xFFFF);
tc_enable_cc_channels(config->freq_opt.timer, TC_CCAEN);
tc_set_resolution(config->freq_opt.timer,
(config->freq_opt.unit / 1000) / config->revolution);
config->freq_opt.coef
= (((uint64_t)tc_get_resolution(config->freq_opt.timer) * 1000)
/ config->freq_opt.unit)
* 4
/ config->revolution;
config->freq_opt.last_freq = 0; /* Initialize frequence to 0Hz */
}
