The 8051 Microcontroller Questions and Answers
The 8051 Microcontroller questions with answers provide a comprehensive overview of microcontroller architecture, instruction sets, and I/O programming. These programming questions and answers are key for embedded systems interviews and ECE placements in companies like TCS, DRDO, and Intel. Each question explores the working principles of timers, interrupts, and serial communication in 8051. Practicing these MCQs enhances your embedded system knowledge and coding efficiency in assembly and C languages.
The 8051 Microcontroller
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59 questions
21. The 8-bit address bus allows access to an address range of:
- 0000 to FFFFH
- 000 to FFFH
- 00 to FFH
- 0 to FH
22. The contents of the accumulator after this operation MOV A,#0BH ANL A,#2CH will be
- 11010111
- 11011010
- 00001000
- 00101000
23. This program code will be executed once: STAT: MOV A, #01H JNZ STAT
- TRUE
- FALSE
24. Which of the following instructions will move the contents of register 3 to the accumulator?
- MOV 3R, A
- MOV R3, A
- MOV A, R3
- MOV A, 3R
25. Which of the following statements will add the accumulator and register 3?
- ADD @R3, @A
- ADD @A, R3
- ADD R3, A
- ADD A, R3
26. Data transfer from I/O to external data memory can only be done with the MOV command.
- TRUE
- FALSE
27. Which of the following commands will move the number 27H into the accumulator?
- MOV A, P27
- MOV A, #27H
- MOV A, 27H
- MOV A, @27
28. This program code will read data from port 0 and write it to port 2, and it will stop looping when bit 3 of port 2 is set: STAT: MOV A, PO MOV P2,A JNB P2.3, STAT
- TRUE
- FALSE
29. Which of the following commands will move the value at port 3 to register 2?
- MOV P2, R3
- MOV R3, P2
- MOV 3P, R2
- MOV R2, P3