In this question data received by UART $0$ will be processed by an Interrupt Service Routine.

a$)$ Write the serial$\_$init$()$ function to initialize UART$0$ as follows:

$$ Receive Only

$9,600$ baud rate

$8$ data bits

$$ Even parity

$2$ stop bit

$$ Disable FIFOs

$$ Enable UART Receive interrupts only

You may initialize unrelated control bits as you wish.

$//$ Initialize UART$0$

void serial$\_$init$()$

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$//$Binds UART$0$ interrupt requests to My$\_$UART$0\_$RX$\_$Handler

$$ IntRegister$($INT$\_$UART$1,$ My$\_$UART$0\_$Handler$)$;

$$ IntMasterEnable$()$;$//$Globally allows CPU to service interrupts

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b$)$ Write code for My$\_$UART$0\_$Handler to implement the Interrupt Service Routine $($ISR$)$ that processes the occurrence of a UART$0$ received data interrupt.$$ In addition, within$$ this ISR turn on an LED connected to GPIO Port B pin $3$ when an $$L$($for Light$)$ is received by UART$0$ by writing a $1$ to the LED, and turn off this LED when an $$O$($for Off$)$ is received by writing a $0$ to the LED.

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$//$ UART$0$ ISR

void My$\_$UART$0\_$Handler$()$

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c$)$ Complete main$()$ to print $$LED turned ON$$ and $$LED turned OFF$$ once each time the LED is turned on or off respectively.

void My$\_$UART$0\_$Handler$()$;

void serial$\_$init$($void$)$;

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volatile int flag $=0$; $//$ Helper variable

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int main$()$

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$$ init$\_$portB$()$; $//$ Assume implemented correctly in Question $2$

$$ serial$\_$init$()$;

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$$ while $(1)$

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$//$Print each time the LED is turned ON or OFF

$//$Hint: make use the helper variable flag declared above.

$//$ YOUR CODE HERE

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$$ return $0$;

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