- * Return the system tick counter (expressed in ms)
- * This function must disable interrupts on 8/16bit CPUs because the
+ * \brief Return the system tick counter (expressed in ms)
+ *
+ * The result is guaranteed to increment monotonically,
+ * but client code must be tolerant with respect to overflows.
+ *
+ * The following code is safe:
+ *
+ * \code
+ * time_t tea_start_time = get_tick();
+ *
+ * boil_water();
+ *
+ * if (get_tick() - tea_start_time > TEAPOT_DELAY)
+ * printf("Your tea, Sir.\n");
+ * \endcode
+ *
+ * When the tick counter increments every millisecond and time_t
+ * is 32bit wide, the tick count will overflow every 49.7 days.
+ *
+ * \note This function must disable interrupts on 8/16bit CPUs because the