+timer_init(u32_t frequency);
+
+struct lx_timer*
+timer_run_second(u32_t second,
+ void (*callback)(void*),
+ void* payload,
+ u8_t flags);
+
+struct lx_timer*
+timer_run_ms(u32_t millisecond,
+ void (*callback)(void*),
+ void* payload,
+ u8_t flags);