Consider the following statements regarding 8051 interfacing to peripherals:1.8051 supports multiple interrupt sources.2.Interrupts can be enabled/disabled.3.Interrupt priority can be configured.Which of the above statements is/are correct?

Correct Answer: A - All of the above

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.
  8051 supports multiple interrupt sources.
  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 2 - Correct.
  Interrupts can be enabled/disabled.
  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.
  Interrupt priority can be configured.
  The standard core has 4 KB on-chip program ROM and 128 bytes internal RAM, supports external memory, multiple interrupts and configurable interrupt priority.

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

Exam Shortcut / Approach

Remember 07H for stack pointer reset.

Common Mistake

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

Quick Revision

Interrupt Enable and Priority is linked with Interrupts, 8051 Microcontroller and Microprocessors and Microcontrollers. Remember 07H for stack pointer reset.