Hi, I tried this example but the isr doent seem to be getting executed.
In the isr i m calling a function to display on 7-segment displays. Otherwise the normal program flow is based on Receiving and Sending data on UART0(using timer1 in 8-bit auto-reload for 9600 baud generation)
You talk about a faint display.
Is it LED or LCD?
If LED, you really should drive the display between the interrupts. You can't (or most definitely shouldn't) be in the interrupt long enough to give enough light.
If LCD, the update frequency affects the "strength" of the display.