Labs‘Codes review(AVR)（1）

Two’s complement (negation) of 0x55 -> r9

1.Write an AVR assembly language program which performs the following operations on values 0x55 and 2310 and puts the result in the given register

ldi r30,0x55;
ldi r31,23;

Bitwise AND -> r16

mov r16,r31;
and r16,r30;

Bitwise OR -> r5

mov r5,r31;
or r5,r30;

Bitwise EOR -> r17

mov r17,r31;
eor r17,r30;

Addition -> r6

mov r6,r31;
add r6,r30;

Difference (subtraction) -> r7

mov r7,r30;
sub r7,r31;

One’s complement (inversion) of 0x55 -> r8 Two’s complement (negation) of 0x55 -> r9

mov r9,r30;
neg r8;

2.Write AVR assembly language code snippets to

Copy the least significant three bits of register r7 to register r8. Other bits of r8 should be 0.

mov r8,r7;
ldi r9,0b00000111;
and r9,r8;

Toggle the most significant four bits of register r9. Other bits should be unchanged.

ldi r10,ob11110000;
eor r10,r9;

Clear the least significant four bits of register r10. Other bits should be unchanged.

ldi r11,0b11110000;
and r11,r10;

Set the most significant four bits of register r11 to be 1. Other bits should be unchanged.

ldi r12,ob11110000;
or r11,r12;