Unable to proces hardware interrupt in arduino due

I am facing problem in External interrupt code. The flow enters the ISR but wont come out and compare the variable "Value" with "Tmp". I am using arduino Due, IDE 1.6.7. Please help me. Attached is the code. i have commented the problem.

E312_CODE_1.ino (4.76 KB)

fun.h (5.9 KB)