Interrupt ISRs not working

[abc123862]

hello. I am new to ARM programming. I have started with This example on Teensy 3.2 . I am a windows user So i made a .bat file out of your provided Make file. I have got the LED blinking with my .bat file using Gcc .
I then moved to PIT configuration. but i could not get it working using interrupts. This is the simple configuration of PIT0 with interrupt
This is my main file ,configuration file to enable interrupt and build file for compiling and linking

s

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i am stuck at this point. looking forward to hearing from you

[mensi]

I don't think the isr handler should be defined extern. Also have a look at https://github.com/mensi/teensy_bare_metal/blob/master/common/systick.c which works very similarly.

[abc123862]

I have got PIT working with interrupt by using arm_cm4.h header file and its source file that contains the functions enable_irq () and disable_irq for a particular interrupt

Now i want to configure a Uart receiver .
So far i have been able to do this
But its not working . Can you help me find the mistake?