Jump to content
mahmoud899

Delay Calculation

Recommended Posts

Hello,

 

I have a Stellaris Launchpad LM4F120XL, I am having troubles calculating delays. I set the System Clock to 20MHz with the following code "SysCtlClockSet(SYSCTL_SYSDIV_10 | SYSCTL_USE_PLL | SYSCTL_XTAL_16MHZ | SYSCTL_OSC_MAIN);". Now I want a 1 second delay, what is the formula I use to be able to calculate the correct number to pass as a parameter to the SysCtlDelay() function so it can give me a 1 seccond delay.

 

Thank You

Share this post


Link to post
Share on other sites

Well, if the delay loop takes 3 cycles, then 

1 second * 20 M Cycles/second / 3 cycles/loop ~= 6,666,667 

 

(Of course using a timer might be more accurate (maybe, if one cares), more elegant, allow the processor to do something else, or just more power efficient if go to sleep.)

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×