for 8254 chip ( programmable interval timer ) there are 6 modes ( M0 to M5) where M0 - interrupt on count ( to interrupt processor after time T ) M1 - retriggerable monoshot m2 - rate generator m3 - square wave generator m4 - software triggered mode m5 - hardware triggered mode

Suggest which mode should be used if processor needs to be repeatedly interrupted after every interval of time T. and also for that mode should it be normal operation or operation with gate disabled.