Consider the following statements regarding 8051 Addressing modes:1.Immediate addressing includes operand in instruction.2.Direct addressing uses memory address explicitly.3.Indirect addressing uses register to hold address.Which of the above statements is/are correct?

Correct Answer: D - 1, 2 and 3

Quick Concept Explanation

The classic 8051 is an 8-bit Harvard-style microcontroller with separate code and data spaces. The standard core has 4 KB on-chip program ROM and 128 bytes internal RAM, supports external memory, multiple interrupts and configurable interrupt priority. Key relation: Reset SP=07H; classic internal RAM=128 bytes; standard ROM=4 KB.

Exam focus: Remember 07H for stack pointer reset. Common trap: 00H is not the reset value of the 8051 stack pointer.

Statement-wise Verification

• Statement 1 - Correct.
  Immediate addressing includes operand in instruction.
  Remember 07H for stack pointer reset.
• Statement 2 - Correct.
  Direct addressing uses memory address explicitly.
  The standard core has 4 KB on-chip program ROM and 128 bytes internal RAM, supports external memory, multiple interrupts and configurable interrupt priority.
• Statement 3 - Correct.
  Indirect addressing uses register to hold address.
  Remember 07H for stack pointer reset.

Core Concept

The classic 8051 is an 8-bit Harvard-style microcontroller with separate code and data spaces. The standard core has 4 KB on-chip program ROM and 128 bytes internal RAM, supports external memory, multiple interrupts and configurable interrupt priority. On reset the stack pointer is 07H, so the first PUSH stores at 08H.

Formula / Key Relationship

Reset SP=07H; classic internal RAM=128 bytes; standard ROM=4 KB.

Why the Other Options Are Wrong

Option A is incorrect because it omits correct statement(s) 3. Option B is incorrect because it omits correct statement(s) 1. Option C is incorrect because it omits correct statement(s) 2.

Exam Shortcut / Approach

Remember 07H for stack pointer reset.

Common Mistake

00H is not the reset value of the 8051 stack pointer.

Quick Revision

Immediate Direct and Indirect Addressing is linked with Addressing Modes, 8051 Microcontroller and Microprocessors and Microcontrollers. Remember 07H for stack pointer reset.