Q$3$a$.[3\mathrm{.}5$ marks$]$ Write a program using an Interrupt Service Routine that does the following :

Waits for a Single High Pulse of $250ms$ on Pin OC$3.$ When the High Pulse goes from High to

low, it turns ON the LED at Port A$,$ RA$3$ and the LED then stays on$.$

You will use the Output Compare OC$1,$ Dual Compare mode with a Single High Pulse $($OCM$=$

$.$ You will use Timer $3$ for the OC with a pre$-$scale value of $256.$ You need to setup OC$3$RS

and $OC3R$ such that $OC3RS-OC3R=200ms$

We need to convert $200ms$ into Timer Clock Cycles. We have Timer $3$ with a fpb is $10Mhz$

and a Precale of $1$:$64.$