Hello,
In my industry we are using tiva tm4c129encpdt controller. Crystal used 25MHz. Controller speed 120MHz I have configured the timer with 1000 mSec value. then i found that it is generating interrupt after 500 mSec then i again adjusted value in timer configuration and double its speed. Then it works fine for 1000msec time interval. After few days again i compiled my code and write it into controller. I found that it is giving interrupt. after 2000mSec then i again changed the timer configuration value.
Every time i am facing this timmer problem in my tm4c129 controller.