Q1Microprocessor and Interfaces

The 8086 instruction set is categorized as follows:

• Data Transfer: Moves data between registers and memory (e.g., MOV, PUSH, POP, XCHG, IN, OUT).
• Arithmetic: Performs addition, subtraction, multiplication, and division (e.g., ADD, SUB, MUL, DIV, INC, DEC).
• Logical: Bitwise AND, OR, XOR, NOT, Shift, and Rotate (e.g., AND, OR, XOR, SHL, ROR).
• String Manipulation: Operations on blocks of memory bytes/words (e.g., MOVS, CMPS, SCAS, LODS).
• Control Transfer: Alters program execution flow conditionally or unconditionally (e.g., JMP, JZ, CALL, RET, LOOP).
• Processor Control: Controls CPU state and flags (e.g., STC, CLC, CLI, STI, HLT).

(i) Sorting an Array (Bubble Sort):

• MOV CX, N-1 ; Number of passes
• OUTER: MOV BX, CX ; Inner loop counter
• LEA SI, ARRAY
• INNER: MOV AL, [SI]
• CMP AL, [SI+1]
• JBE SKIP ; Jump if already sorted
• XCHG AL, [SI+1]
• MOV [SI], AL ; Swap elements
• SKIP: INC SI
• DEC BX
• JNZ INNER
• LOOP OUTER
• HLT

(ii) Finding the Largest Element:

• LEA SI, ARRAY ; Point to array start
• MOV CX, N ; Total elements
• MOV AL, [SI] ; Assume first is largest
• DEC CX ; Decrement counter
• INC SI
• NEXT: CMP AL, [SI]
• JAE SKIP ; Jump if AL >= [SI]
• MOV AL, [SI] ; Update AL with new largest
• SKIP: INC SI
• LOOP NEXT
• MOV LARGEST, AL ; Store result
• HLT