c07_ps03_sol

c07_ps03_sol - ; Program name : Subtraction using add only...

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C7 1. Write an algorithm to implement the subtraction operation for two positive integers in assembly language. 1. Let the numbers be A, B and the operation be A-B 2. Convert A into binary 3. Convert B into binary 4. Compute 2’s complement of B i. Invert the bits in B using B xor 11111111 ii. Add 1 to B 5. Add A and the 2’s complement of B. 2. Implement your algorithm in the assembly language describe in the machine language handout. Test your implementation using the SimpleSim simulator.
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Unformatted text preview: ; Program name : Subtraction using add only ;Programmer : Joe B ;Last Modified : Sep 16 2003 load R1, 1 ;1 added for computing 2's complement load R2, FFh ;mask for flipping the bits load R3,first_number ; load R4, second_number ; xor R5, R4,R2 ; flip the 0's and 1's in the second number addi R5,R5,R1 ; add 1 to the flipped bits to get the 2's complement addi R5,R5,R3 ; add the numbers to obtain A - B halt first_number: db 8 ;A in A-B second_number: db 5 ;B in A-B...
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This note was uploaded on 01/28/2012 for the course AERO 16.01 taught by Professor Markdrela during the Fall '05 term at MIT.

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