/**
* \brief Initialize Timer/Counters used to simulate oven actuation signal
*
* TCC0 is set up to generate a dual variable frequency signal with dead-time
* insertion using the AWEX module. This is similar to how heating elements are
* actuated in real induction ovens. Its output is on pin C2 which is marked as
* RXD on header J1.
*
* TCC1 is set up to capture a frequency signal via a pin change event using the
* XMEGA Event System. Its input is pin C4 which is marked as SS on header J1.
*/
void main_init_tc(void)
{
/* Set up timer for PWM output, used to actuate cooking element */
tc_enable(&OVEN_FREQ_TC);
/* Configures the waveform generator in Frequency generation mode */
tc_set_wgm(&OVEN_FREQ_TC, TC_WG_FRQ);
/* Configures the CCA level. This controls frequency generation */
tc_write_cc(&OVEN_FREQ_TC, TC_CCA, FREQ_TIMER_PERIOD_INIT / 2);
/* Enables and configures the deadtime of AWEX channel B outputs */
tc_awex_enable_ccb_deadtime(&AWEXC);
tc_awex_set_dti_high(&AWEXC, FREQ_TIMER_PERIOD_INIT / 4);
tc_awex_set_dti_low(&AWEXC, FREQ_TIMER_PERIOD_INIT / 4);
/* Output of AWEX channel B is on pins C2 and C3 */
tc_awex_set_output_override(&AWEXC, 0x0C);
/* Make sure that the output is initially turned off */
tc_write_clock_source(&OVEN_FREQ_TC, TC_CLKSEL_OFF_gc);
/* Set up timer for input capture for the simulation to read "real"
* power
*/
tc_enable(&OVEN_FREQ_CAPT_TC);
/* Select Event Channel 1 as input to the timer, and perform frequency
* capture.
*/
tc_set_input_capture(&OVEN_FREQ_CAPT_TC, TC_EVSEL_CH1_gc,
TC_EVACT_FRQ_gc);
/* Enable Capture Channel A */
tc_enable_cc_channels(&OVEN_FREQ_CAPT_TC, TC_CCAEN);
/* Make sure pin C4 is configured for input and sensing on rise and fall
* and pin C2 is configured for output.
*/
ioport_configure_pin(J1_PIN4, IOPORT_DIR_INPUT | IOPORT_BOTHEDGES);
ioport_configure_pin(J1_PIN2, IOPORT_DIR_OUTPUT);
/* Turn on power to the event system */
PR.PRGEN &= ~PR_EVSYS_bm;
/* Use pin C4 as input to Event Channel 1 */
EVSYS.CH1MUX = EVSYS_CHMUX_PORTC_PIN4_gc;
/* Turn on timer used for input capture */
tc_write_clock_source(&OVEN_FREQ_CAPT_TC, TC_CLKSEL_DIV256_gc);
}
static void qdec_enabled_tc(qdec_config_t *config)
{
/* Configure TC for quadrature decode for event action and
* event channel selection:
* - Set event source and event action as per sent parameters
* - Load Period register of TC with number of counts for single
* revolution
* - Write clock value and start timer
*/
tc_enable(config->timer);
tc_set_input_capture(config->timer,
(TC_EVSEL_t)(TC_EVSEL_CH0_gc + config->event_channel),
TC_EVACT_QDEC_gc);
tc_write_count(config->timer, 0);
tc_write_period(config->timer, config->revolution - 1);
tc_write_clock_source(config->timer, TC_CLKSEL_DIV1_gc);
}
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 */
}
