up_disable_irq()up_enable_irq()up_prioritize_irq()
- 4.1.19 up_putc()
+ 4.1.19 up_putc()
+ 4.1.20 System Time and Clock
4.2 APIs Exported by NuttX to Architecture-Specific Logic
make.
Output one character on the console
++ To enable UTC time representation use option: +
++CONFIG_SYSTEM_UTC=y ++
+ which adds the following variables: +
+g_system_utc (seconds, 4 bytes)g_tickcount (timer ticks, 1-2 bytes typically)+ and replaces: +
+g_system_timer(4 bytes)g_basetime(8 bytes)g_tickbias(4 bytes)
+ Otherwise internal time is computed from 32-bit running tick timer
+ g_systemtimer the start date g_basetime and time offset the g_tickbias.
+
+ To enable hardware module use option: +
+
+CONFIG_RTC=y ++
+ which requires the following three base functions to read time: +
+up_rtcinitialize()up_rtc_gettime(). UTC time in seconds.up_rtc_getclock(). Replacement for g_system_tick
+ This module depends on CONFIG_SYSTEM_UTC=y.
+
+ The system tick is represented by, when CONFIG_SYSTEM_UTC=n:
+
g_system_timer
+ or, when CONFIG_SYSTEM_UTC=y
+
g_tickcountg_system_utc+ Running at rate of system base timer, used for time-slicing, and so forth. +
+
+ If hardware RTC is present (CONFIG_RTC) and enabled, then after successful
+ initiliazation variables are overriden by calls to up_rtc_getclock() which is
+ running continously even in power-down modes.
+
+ In the case of CONFIG_RTC is set the g_tickcount and g_system_utc keep
+ counting at rate of a system timer, which however, is disabled in power-down
+ mode. By comparing this time and RTC (actual time) one may determine the
+ actual system active time. To retrieve that variable use:
+
+
clock_gettime(CLOCK_ACTIVETIME, tp)
+
+
+ If the CLOCK_ACTIVETIME time is never set it will serve as power-up time
+ minus all deep sleeps.
+
These are standard interfaces that are exported by the OS