Micro

In 32-bit multiplication using MUL, where is the 64-bit product stored?. AX only. DX:AX. EDX:EAX. RDX:RAX.

Which instruction performs subtraction and also subtracts the borrow stored in the carry flag?. SUB. DEC. CMP. SBB.

What is the main difference between CMP and SUB instructions?. CMP changes the destination operand. CMP only affects flags, not operands. SUB does not affect flags. CMP performs addition instead of subtraction.

After executing INC [DI], why must BYTE PTR or WORD PTR be specified?. To indicate signed or unsigned operation. To specify the size of the operand. To enable carry propagation. To allow segment register access.

Which instruction inverts all bits of a byte, word, or doubleword?. NEG. NOT. XOR. TEST.

Logical shift left by two positions on an unsigned integer is equivalent to: Division by 4. Multiplication by 4. Addition of 2. Subtraction of 2.

During 8-bit division using DIV, where are the quotient and remainder stored?. Quotient in AX, remainder in DX. Quotient in AL, remainder in AH. Quotient in EAX, remainder in EDX. Quotient in BL, remainder in BH.

Which addressing mode calculates the effective address by adding a constant displacement to a base register?. Immediate. Direct. Indexed (Displacement). Register.

In machine language, which field determines whether the instruction uses register addressing or memory addressing?. REG. MOD. R/M. W.

If MOD = 11 in the second byte of an instruction, what does it indicate?. Memory addressing with displacement. Register addressing mode. Immediate addressing. Indexed addressing.

Which instruction pushes all 16-bit general-purpose registers onto the stack in the order AX, CX, DX, BX, SP, BP, SI, DI?. PUSHF. PUSHA. PUSHAD. POPA.

After executing PUSHA on an 80286 processor, how many bytes of stack memory are used?. 8 bytes. 16 bytes. 32 bytes. 64 bytes.

Which instruction transfers a byte from an I/O device into memory addressed by DI using DX as the I/O port?. OUTS. INS. MOVS. STOS.

If the direction flag (D) is set using STD, what happens during string operations?. SI and DI auto-increment. SI and DI auto-decrement. SI increments, DI decrements. No change in SI and DI.

In the instruction MOV DL, [DI+1], what is the MOD field value in machine code?. 00. 01. 10. 11.

Which string instruction transfers data from memory addressed by SI to an I/O device addressed by DX?. INS. OUTS. MOVS. STOS.

Which of the following statements about register addressing is correct?. It uses register names such as AH, AL, BH, BL for 8-bit operations. It allows data to be addressed through an offset stored in memory. It requires a displacement added to the segment address. It is only available in 80386 and above processors.

Which addressing mode uses both a base register and an index register to calculate the effective address?. Register indirect addressing. Direct addressing. Base-plus-index addressing. Immediate addressing.

In program memory addressing, which form is commonly used for jumps relative to the instruction pointer (IP)?. Direct addressing. Relative addressing. Indirect addressing. Displacement addressing.

Which registers maintain the stack in stack memory addressing mode?. BX and BP. SP (or ESP) and SS. AX and DX. CS and IP.

Which statement correctly explains the role of program-invisible registers in protected mode operation?. They store the offset address for real mode memory access. They cache descriptor information for faster segment access. They hold privilege level information for flat mode addressing. They directly store the base address of the global descriptor table.

In protected mode, what is the function of the TI bit in a segment selector?. It determines the privilege level of the segment. It selects between global and local descriptor tables. It specifies the direction of segment growth. It indicates whether the segment is code or data.

Which of the following conditions triggers a general protection fault in protected mode?. Loading a null descriptor into a segment register. Using a segment with write-protection for a write operation. Accessing memory beyond the 1M-byte limit. Using a flat memory model without privilege levels.

Why does flat mode memory eliminate segmentation overhead?. It uses descriptors with unlimited size. It replaces segment registers with 64-bit offsets. It addresses memory using a single continuous 40-bit address space. It uses paging instead of segmentation for memory access.

Which register combination is used by default to locate the next instruction in real mode?. CS and RIP. DS and IP. CS and IP. SS and SP.

Which feature of the Intel 8080 microprocessor most significantly improved interfacing compared to the 8008?. Increased instruction set size. TTL compatibility. Higher clock frequency. Expanded memory addressing.

Why did Intel introduce the 80286 microprocessor despite the 8086 already supporting 1M byte memory?. To improve instruction set complexity. To enable protected mode and address larger memory systems. To reduce transistor count for cost efficiency. To integrate floating-point operations.

Which of the following correctly describes the memory addressing capability of Pentium Pro in server configurations?. 4G bytes using a 32-bit address bus. 64G bytes using a 36-bit address bus. 1T bytes using a 40-bit address bus. Unlimited memory using flat mode.

In the context of bus architecture, which statement is true for the address bus in modern Intel processors?. It transfers both data and control signals. Its width determines the maximum memory addressable. It is bidirectional for memory read and write operations. It operates independently of the data bus width.

What was the primary reason Intel transitioned from numeric naming (e.g., 80586) to the “Pentium” brand?. To indicate 64-bit architecture. To differentiate consumer and server processors. To reflect MMX technology integration. To avoid copyright issues with numeric names.

A PIC16F877A microcontroller is configured with TRISB = 0x03. Which statement is TRUE?. RB0 and RB1 are inputs, others are outputs. All PORTB pins are outputs. RB0 and RB1 are outputs, others are inputs. All PORTB pins are inputs.

If a watchdog timer is not refreshed in a running program, what happens?. The microcontroller continues execution normally. The microcontroller enters sleep mode. The microcontroller disables all interrupts. The microcontroller resets automatically.

Which of the following configurations will make PORTC pins RC0–RC3 inputs and RC4–RC7 outputs in PIC16F877A?. TRISC = 0xF0. TRISC = 0x0F. TRISC = 0xFF. TRISC = 0x00.

A PIC microcontroller uses an external RC oscillator with R=10kΩ and C = 30 pF . Approximate clock frequency is: 10 MHz. 3 MHz. 10 MHz. 100 MHz.

Which of the following statements about embedded systems is FALSE?. They always use general-purpose microprocessors. They are designed for real-time operations. They often include mechanical and electrical components. They perform dedicated functions within a larger system.

Which of the following best explains why microcontrollers are preferred over microprocessors in embedded systems?. They have higher processing power. They require external components for I/O. They integrate CPU, memory, and peripherals on a single chip. They consume more power.

A PIC16F877A has 8K words of flash memory. If each instruction is 14 bits, what is the total program memory size in bytes?. 8 KB. 14 KB. 16 KB. 11 KB.

Which of the following clock sources provides the highest accuracy for PIC microcontrollers?. Internal oscillator. External RC oscillator. External crystal oscillator. Software delay loops.

If TRISB = 0x03 and PORTB = 0xFF, what will be the logic level at RB0 and RB1 pins?. High. Low. Undefined (depends on external circuit). Alternating.

Which instruction adds two operands and stores the sum in the destination while copying the original destination value into the source?. ADD. ADC. XADD. INC.