CO-Lab6

$I$

What does the following code? (There are 3 instructions.)

0011000000000000 1001001001111111 0001010001100001 0001010000000010

$NOT$ $R_1$ $R_1$$ADD$ $R2$ $R1$ $\mathrm{\#}1$$ADD$ $R2$ $R0$ $R2$

$II$

Input the following code and try to understand what it does by executing it step by step. (There are 6 instructions.)

LEA R1, x2FFE ADD R2, R1, #14 AND R2, R2, #0 ADD R2, R2, #5 STR R2, R1, #14 LDI R3, x2FFD

Firstly, it load x2FFE to R1 then ADD 14 to R1's content and store it into R2 then AND 0 with R2 and store its result to R2 then ADD 5 to R2 and store its result to R2 then Store R2's content to the address that is R1's content plus 14 finally x2FFD plus PC's content then find the address's content,using this content to find the address and load the content to R3

$III$

Write a LC3 machine code program to print out “Hello World!”. Hint: consider to use Trap instruction PUTS.

1110 0000 0000 0010 1111 0000 0010 0010 1111 0000 0010 0101 0000 0000 0100 1000