precision wall clock

mechanism is introduced on the basis of PTP protocol, and the method of filtering and linear fitting is adopted to realize the clock synchronization of millisecond precision.　3.1 Construction of high-precision clocksFor a system, the clock can be divided into two kinds, the physical

come, don't leave with regret, so we without further ado, buy tickets upstairs.The bell tower was 22 storeys, and we went to the second floor after a round of upstairs. Outside the door of the second floor, you can jump to the whole XI ' an city. The bell tower is located in the center of Xi ' an city, East 4 directions can see XI ' an wall of 4 doors.Then on the second floor to see XI ' an all kinds of ceremonial style of bread, such as the full moo

One, wall clock time, user CPU time, System CPU time definition and contactClock time (Wall clock time): The time that the clock passes from the start of the process to the end, which contains the time at which the process is blocking and waiting.User CPU Time: Is the user's

In a recent project, a high-precision real-time clock is required under VxWorks, with a precision of 1ms and an overflow time of more than 5 hours. The VxWorks provides a system clock that starts counting after the operating system starts, with a precision of 1 ticks, and ca

Test instructions: Given a start time and an angle, ask you the next moment the hour and minute hand form this angle is a few points.Analysis: Anyway the number is very small, you can consider violence, starting from the first second violence, until that angle can, will not time out, the number is few, but pay attention to precision.The code is as follows:#include HDU 5705 Clock (Precision control, violence

DS3231 high-precision clock module is cheap and easy to use, SDA/SCL two IO ports can handle the basic functions, but when using the alarm interrupt output encountered a problem, that is, the alarm interrupt will only output once, and then always keep low level.This problem data sheet does not explicitly, in the online search for a long time, a little information has not been found, had to toss themselves.A

; - } - return 0; - } + intMainintargcChar**argv) - { + structtimeval Start,stop,diff; Amemset (start,0,sizeof(structtimeval)); atmemset (stop,0,sizeof(structtimeval)); -memset (diff,0,sizeof(structtimeval)); -Gettimeofday (start,0); - //do what you have to do ... -printf"Hello world\n"); -Gettimeofday (stop,0); inTime_substract (diff,start,stop); -printf"Total time:%d s,%d us\n",(int) Diff.tv_sec, (int) diff.tv_usec); to}Operation Result:reprinted from: Http://blog.chinaunix.net

//////////////////////////////////////// ////// High-resolution timer // multimedia high-precision clock application class /////////////////////// /// // # include // Application. h chighresolutiontimer mm_timer; static void timercallback (DWORD dwuser); // application. CPP timer callback void cmy_timerdlg: timercallback (DWORD dwuser) {cmy_timerdlg * pthis = (cmy_timerdlg *) dwuser; // static Long Coun