I need some help with code assembly for attiny$1626.$ I cant seem to do ex$2\mathrm{.}1$ and $2\mathrm{.}8$

$.$section $.$init$0$

entry:

ldi r$16,0$xFF

mov r$1,$ r$16$

ldi r$22,0$x$10$

ldi r$16,0$xCC

mov r$4,$ r$16$

$//$ DO NOT EDIT ABOVE THIS LINE $//$

$//$ WARNING:

$//$

$//$ Do not modify the data in the following registers unless

$//$ specified by the exercise:

$//$

$//$ R$1($Ex $2\mathrm{.}1)$

$//$ R$4($Ex $2\mathrm{.}9)$

$//$ R$20($Ex $2\mathrm{.}2)$

$//$ R$22($Ex $2\mathrm{.}6)$

$//$ Ex $2\mathrm{.}0$

$//$

$//$ Write assembly code to add the numbers $53$ and $34$ together and

$//$ store the result in register R$0.$

$//$

$//$ Hint:

$//$ Recall the "ldi" instruction loads a value into a register, and

$//$ the "mov" instruction copies a value between registers.

ldi r$16,53$ ; Load $53$ into r$16$

ldi r$17,34$ ; Load $34$ into r$17$

add r$16,$ r$17$ ; Add r$17$ to r$16$

mov r$0,$ r$16$ ; Move the result to r$0$

$//$ Write your code for Ex $2\mathrm{.}0$ above this line.

mov r$16,$ r$0$

call avremu$\_$r$16$out

$//$ Ex $2\mathrm{.}1$

$//$

$//$ Using the "and" instruction, clear only bits $2,3,$ and $7$ of R$1.$

mov r$16,$ r$1$ ; Copy the value of R$1$ to R$16$

; Use an "and" instruction to clear the desired bits in R$16$

andi r$16,0$b$10001100$ ; Clear bits $2,3,$ and $7$ in R$16$

mov r$1,$ r$16$ ; Move the result back to R$1$ if necessary

$//$ Write your code for Ex $2\mathrm{.}1$ above this line.

mov r$16,$ r$1$

call avremu$\_$r$16$out

$//$ Ex $2\mathrm{.}2$

$//$

$//$ Using the "ori" instruction, set only bits $1,3,$ and $5$ of R$20.$

ori r$20,0$b$00101010$

$//$ Write your code for Ex $2\mathrm{.}2$ above this line.

mov r$16,$ r$20$

call avremu$\_$r$16$out

$//$ Ex $2\mathrm{.}3$

$//$

$//$ Using exactly one instruction, add $1$ to the value of R$0.$

$//$

$//$ Hint:

$//$ You can find a full list of arithmetic instructions summarised

$//$ in Table $5-2$ of the AVR Instruction Set Manual.

inc r$0$ ; Increment the value in r$0$ by $1$

$//$ Write your code for Ex $2\mathrm{.}3$ above this line.

mov r$16,$ r$0$

call avremu$\_$r$16$out

$//$ Ex $2\mathrm{.}4$

$//$

$//$ Write assembly code to add $44$ to $14685,$ storing the result in

$//$ register pair R$31$:R$30($low byte in R$30).$

ldi r$31,0$x$39$

ldi r$30,0$x$5$D

adiw r$30,0$x$2$C

$//$ Write your code for Ex $2\mathrm{.}4$ above this line.

mov r$16,$ r$30$

call avremu$\_$r$16$out

mov r$16,$ r$31$

call avremu$\_$r$16$out

$//$ Ex $2\mathrm{.}5$

$//$

$//$ Follow the steps below to complete this exercise.

$//$

$//$ Step $1$: Encode the decimal value $-4$ as a two's complement, $8-$bit number.

$//$ Step $2$: Write down the result of Step $1$ as a hexadecimal literal.

$//$ Step $3$: Swap the two nibbles of the hexadecimal literal you wrote in Step $2.$

$//$ Step $4$: Load the result of Step $3$ into register R$21.$

ldi r$21,0$b$11001111$ ; Load the high nibble $(1100)$ into r$21$

$//$ Write your code for Ex $2\mathrm{.}5$ above this line.

mov r$16,$ r$21$

call avremu$\_$r$16$out

$//$ Ex $2\mathrm{.}6$

$//$

$//$ Write assembly code to subtract the value in R$22$ from $91$ using

$//$ the "add" instruction, storing the result in R$23.$

ldi r$16,91$ ; Load $91$ into r$16$

sub r$16,$ r$22$ ; Subtract the value in r$22$ from $91$ and store the result in r$23$

mov r$23,$ r$16$ ; Move the result to r$23$

$//$ Write your code for Ex $2\mathrm{.}6$ above this line.

mov r$16,$ r$23$

call avremu$\_$r$16$out

$//$ Ex $2\mathrm{.}7$

$//$

$//$ Write assembly code to multiply the number $20$ by $2$ using the

$//"$lsl$"$ instruction, storing the result in R$2.$

ldi r$16,20$ ; Load the value $20$ into R$16.$

lsl r$16$ ; Multiply R$16$ by $2$ using the "Logical Shift Left" instruction.

mov r$2,$ r$16$ ; Copy the result from R$16$ to R$2.$

$//$ Write your code for Ex $2\mathrm{.}7$ above this line.

mov r$16,$ r$2$

call avremu$\_$r$16$out

$//$ Ex $2\mathrm{.}8$

$//$

$//$ Write assembly code to divide the number $-37$ by $4$ using the "asr"

$//$ instruction, storing the result in R$3.$

ldi r$16,0$xDB ; Load $-37$ into r$16($two$\text{'}$s complement$)$

asr r$16$ ; Arithmetic shift right to divide by $4$

mov r$3,$ r$16$ ; Move the result to r$3$

$//$ Write your code for Ex $2\mathrm{.}8$ above this line.

mov r$16,$ r$3$

call avremu$\_$r$16$out

$//$ Ex $2\mathrm{.}9$

$//$

$//$ Write assembly code to toggle the most significant bit, and least

$//$ significant $4$ bits of R$4.$

ldi r$16,0$x$80$ ; Load a mask with the most significant bit set $($binary: $10000000)$

eor r$4,$ r$16$ ; Toggle the most significant bit of r$4$

ldi r$16,0$x$0$F ; Load a mask with the least significant $4$ bits set $($binary: $00001111)$

eor r$4,$ r$16$ ; Toggle the least significant $4$ bits of r$4$

$//$ Write your code for Ex $2\mathrm{.}9$ above this line.

mov r$16,$ r$4$

call avremu$\_$r$16$out

$//$ END OF TUTORIAL$02$ EXERCISES $//$

$//$ DO NOT EDIT BELOW THIS LINE $//$

ldi r$16,0$x$22//$ DISP$\_$EN $($PB$1)|$ DISP$\_$DP $($PB$5)$

sts $0$x$0420,$ r$16//$ Set as outputs

sts $0$x$0424,$ r$16//$ Drive high

break

ldi r$16,0$x$20//$ DISP$\_$DP $($PB$5)$

ldi r$17,0$x$00$

loop:

$//$ Delay

com r$17$

brne loop

inc r$18$

brne loop