Question $4(15$ Marks$)$

a$.$ The unfinished program in Figure $3$ is to be used to continuously measure the pulse width of a $50$ Hz square wave. The square wave is sent to the input capture pin of the ATMega$32.$ The program uses a prescaler value that gives the pulse width in microsecond $($us$)$ using a $16$ bits $(2$ bytes$)$ data type. The lower byte of the result is displayed on PORTA and the upper byte on PORTB. Assuming XTAL $\backslash (=8\backslash$mathrm$\{$MHz$\}\backslash )$ and the timer is operated in normal mode. Complete the program by filling in the missing information wherever a question sign $(?)$ occurs in Figure $3.$

$```$

#include

int main $()$

l

unsigned int tl$,$t$2,$ Period;

DDRD $=?$; $///1/2$ Mark$]$

DDRA $=?$; $\backslash /1/2$ Mark$]$

DDRB $=?$; $///1/2$ Mark$]$

TCCR$1$A $=?$; $//[1/2$ Mark$]$

while$($l$)$

l

TCCR$1$B $=2$; $//[2$ Marks$/$

while $(($TIFR& $($l$$