Problem $16$: $(60$ points$)$

Refer to the circuit diagram in Figure $1$ and the C code in Figure $3$ for the dsPIC$33$EP$64$MC$502$ microcontroller.

$(6$ points$)$ Complete the initialize$\_$IO$\_$ports$()$ function to configure pin $21$ for the interrupt signal, and include comments for each line.

$(12$ points$)$ Complete line $30$ to assign INT$1$ to pin $21.$

$(12$ points$)$ Complete the initialize$\_-$INT$()$ function.

$(10$ points$)$ Add comments to lines $30-34.$

$(6$ points$)$ Complete lines $38$ and $39.$

$(14$ points$)$ Refer to Table $4-32,$ Table $4-7$ and Register $7-4$ in the datasheet of dsPIC$33$EP$64$MC$502.$ Modify the codes to assign INT$2$ instead of INT$1$ to pin $21.$ Include the line numbers and corresponding modified codes$\mathrm{.}24$

$25$

$26$

$27$

$28$

$29$

$30$

$31$

$32$

$33$

$34$

$35$

$36$

$37$

void initialize$\_$INT $($void$)\{$

$38$

$$

$39$

$40$

void $q,$ attribute $q,$

$q,$

$q,,$auto$\_$psv$))\_$INT$1$Interrupt $($void$)\{$

$\}$

$//$

$\{//$ Turn off LED $//$ clear interrupt flag b

Figure $3$: C code for Problem $16.$