Question $5$:

$5$ MARKS

missing registers in Hex format and use masking operators if required.

#define F$\_$CPU $8000000$ UL

int main $()$

$1$

unsigned char $x$ :

unsigned char result :

ADMUX

ADCSRA $=$

I$/(1)$ choose channel $2,$ left adjust, ref$=$AREF

while $(1)\{$

$//(2)$ enable ADC, divide clock by $64$

ADCSRA $=$

;$/$l $(3)$ make it start conversion.

do $\{$

$x=$ ADCSRA &

$\}$ while $)=(0$;

result $=$

I$/(4)$ detecl the end of conversion

$\}$ ;$/$I $(5)$ take only the most significant $8$ bits of the result

$\frac{1}{?}$ and discard the least significant two bits. You may choose ADLAR value accordingly

$//$ the rest of the code is ommitted.

Question $6$:

$9$ MARKS

You are required to design an LED brightness controller using Timer $0$ on Atmega $8$ microcontroller. The program should generate a PWM signal to control the brightness of an LED $($connected to PB$3).$ You may follow the instructions given in the code below to complete the program.

For configuration of Ports and registers, you are required to use masking and shifting operators. $[8$ Marks$]$

#include $$avr$/$io$.$h$>$ #include $1MHz$