+uint64_t
+ao_time_ns(void)
+{
+ AO_TICK_TYPE before, after;
+ uint32_t cvr;
+
+ do {
+ before = ao_tick_count;
+ cvr = stm_systick.cvr;
+ after = ao_tick_count;
+ } while (before != after);
+
+ return (uint64_t) after * (1000000000ULL / AO_HERTZ) +
+ (uint64_t) cvr * (1000000000ULL / AO_SYSTICK);
+}
+
+#endif
+