Hi Russell,

Thank you very much for your reply,

There is no problem with the thryistor of the thyristor driving circuitary control board etc. I have tried writing a small program which simply monitors the zero cross port pin P3^2 by polling and waits for a state change the moment it detects a change it starts timer 0 to count a delay of 6ms and when this elapses it sends 10 pulses to the thyristor to fire it and this whole thing is a continuous super loop. With this small program the lamp shows no flickering at all. Thus it indicates nothing wrong with the hardware of setup but certianly something wrong with my these interrupt routines.

Thanks & Regards,
Prahlad Purohit