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#include "project.h"
static volatile uint32_t ticks;
static uint32_t scale = 30;
unsigned led = 32000;
void
delay_us (uint32_t d)
{
d *= scale;
while (d--)
__asm__ ("nop");
}
void
sys_tick_handler (void)
{
timex_tick();
cdcacm_tick();
ticks++;
if (led) {
gpio_clear (LED1_BANK, LED1_GPIO);
gpio_clear (LED2_BANK, LED2_GPIO);
led--;
} else {
gpio_set (LED1_BANK, LED1_GPIO);
gpio_set (LED2_BANK, LED2_GPIO);
}
}
void
ticker_init (void)
{
uint32_t v, w;
/*Start periodic timer */
systick_set_clocksource (STK_CSR_CLKSOURCE_AHB);
systick_set_reload (2288);
/* 72MHz / 2288 => 31.469531kHz (we wanted 31.46875) */
systick_interrupt_enable();
systick_counter_enable();
/*Calibrate the delay loop */
do {
scale--;
v = ticks;
while (v == ticks)
;
delay_us (32);
w = ticks;
v++;
w -= v;
} while (w);
}
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