readme-timestamp

Curtiss-Wright Controls Embedded Computing公司的cw183板bsp源代码

README - timestampT.c

This timestamp demo has three functions:

timestampTest()		- main routine to be called for the timestamp test
timestampInterval()	- routine used as a task to display timestamp data at certain 	
			  intervals
timestampRollover()	- routine called when an interrupt occurs during the timestamp 
			  roll-over


timestampTest(): 

		This is the main routine that you will call to run the test. This routine 
		installs the timestamp ISR, spawns a task and uses a semaphore to capture
		that task. The task that was spawned calls the timestampInterval routine 
		and when the timestamp device rolls-over, the interrupt calls the 
		timestampRollover routine. The time it takes the timestamp device to roll 
		over is estimated to be about 85 seconds. 

		In order to run the test, execute timestampTest in your shell and 
		follow the prompts (an example of a typical output can be found below).
			

timestampInterval(): 	
		
		This routine's purpose is to check the time interval between two given 
		timestamps and ensure that this time is accurate according to the time
		interval given by the user. It also adjusts for when a rollover occurs 
		so that there are no discrepencies with the time intervals. 
		

timestampRollover():

		This routine is invoked upon a roll-over of the timestamp device. It raises
		a flag for the timestampInterval routine, telling it that the timestamp 
		device has rolled over. This routine also calculates the time it has taken 
		since the beginning of timestampTest to roll-over.


The following is an example of the typical output for the timestampTest:

-> timestampTest

Enter desired Time Interval(between 1 and 40 seconds): 10
Enter desired number of Iterations: 9


********************************************************
*                Timestamp Test Started                *
********************************************************

The test will run 9 times at 10 second intervals...


Initial timestamp:              3108 ticks
System timestamp period:        4294967295 ticks
System timestamp frequency:     50000000   Hz
________________________________________________________

Delta between ticks:     9.999985 seconds
Accuracy of delta:      99.998474 %

Delta between ticks:     9.999984 seconds
Accuracy of delta:      99.998383 %

Delta between ticks:     9.999986 seconds
Accuracy of delta:      99.998566 %

Delta between ticks:     9.999986 seconds
Accuracy of delta:      99.998566 %

Delta between ticks:     9.999986 seconds
Accuracy of delta:      99.998566 %

Delta between ticks:     9.999986 seconds
Accuracy of delta:      99.998566 %

Delta between ticks:     9.999985 seconds
Accuracy of delta:      99.998474 %

Delta between ticks:     9.999986 seconds
Accuracy of delta:      99.998566 %

________________________________________________________

A roll-over has occurred at 85 seconds.
________________________________________________________


Delta between ticks:     9.999986 seconds
Accuracy of delta:      99.999855 %

________________________________________________________

Time to run the test:   90 seconds
Number of rollovers:    1
Timestamp rollover 1:   4294967295 ticks
Final timestamp:        216980876 ticks

********************************************************
*               Timestamp Test Completed               *
********************************************************