Multiple Choice Questions & Answers on 8051 I/O Port Programming and Addressing Modes 1. Auto reload mode is allowed in which mode of the timer? a) Mode 0 b) Mode 1 c) Mode 2 d) Mode 3 Answer: Mode 2 2. If Timer 0 is to be used as a counter, then at what particular pin clock pulse need to be applied? a) P3.3 b) P3.4 c) P3.5 d) P3.6 Answer: P3.4 3. What is the maximum delay that can be generated with the crystal frequency of 22MHz? a) 2978.9 sec b) 0.011 msec c) 11.63 sec d) 2.97 msec Answer: 2.97 msec 4. In the instruction “MOV TH1,#-3”, what is the value that is being loaded in the TH1 register? a) 0xFCH b) 0xFBH c) 0xFDH d) 0xFEH Answer: 0xFDH 5. TF1, TR1, TF0, TR0 bits are of which register? a) TMOD b) SCON c) TCON d) SMOD Answer: TCON 6. Find out the roll over value for the timer in Mode 0, Mode 1 and Mode 2? a) 00FFH,0FFFH,FFFFH b) 1FFFH,0FFFH,FFFFH c) 1FFFH,FFFFH,00FFH d) 1FFFH,00FFH,FFFFH Answer: 1FFFH,FFFFH,00FFH. 7. What is the clock source for the timers? a) some external

8051 microcontroller MCQ 1. ANL instruction is used _______ a) to AND the contents of the two registers b) to mask the status of the bits c) all of the mentioned d) none of the mentioned Answer: all of the mentioned 2. CJNE instruction makes _______ a) the pointer to jump if the values of the destination and the source address are equal b) sets CY=1, if the contents of the destination register are greater then that of the source register c) sets CY=0, if the contents of the destination register are smaller then that of the source register d) none of the mentioned Answer: none of the mentioned 3. XRL, ORL, ANL commands have _______ a) accumulator as the destination address and any register, memory or any immediate data as the source address b) accumulator as the destination address and any immediate data as the source address c) any register as the destination address and accumulator, memory or any immediate data as the source address d) any register as the destination address and any i

Multiple Choice Questions & Answers on 8051 Interfacing 1. An electronic device which converts physical quantity or energy from one form to another is called ______ a) Sensor b) Transistor c) Transducer d) Thyristor Answer: Transducer 2. A thermistor is a __________ a) sensor b) adc c) transducer d) micro controller Answer: transducer 3. DS12887 is a ____________ a) Timer IC b) Serial communication IC c) RTC IC d) Motor Answer: RTC IC 4. DS12887 has _____ amount of RAM. a) 14 bytes b) 114 bytes c) 128 bytes d) 64 bytes Answer: 128 bytes 5. The 8255 is a ______ chip. a) Input/Output b) Analog to Digital c) Digital to analog d) None of the mentioned Answer: Input/Output 6. DS12887 has _____ amount of RAM for general purpose applications. a) 9 bytes b) 114 bytes c) 128 bytes d) 14 bytes Answer: 114 bytes 7. How many pins of the 8255 can be used as the I/O ports? a) 8 b) 16 c) 24 d) 32 Answer: 24 8. LM35 has how many pins? a) 2 b) 1 c) 3 d) 4 Answer: 3 9. Find the control word for PA =

Multiple Choice Questions & Answers on 8051 Microcontroller I/O Port Programming and Addressing Modes 1. Which operator is the most important while assigning any instruction as register indirect instruction? a) $ b) # c) @ d) & Answer: @ 2. Which of the following comes under the indexed addressing mode? a) MOVX A, @DPTR b) MOVC @A+DPTR,A c) MOV A,R0 d) MOV @R0,A Answer: MOVC @A+DPTR,A 3. Which out of the four ports of 8051 needs a pull-up resistor for using it is as an input or an output port? a) PORT 0 b) PORT 1 c) PORT 2 d) PORT 3 Answer: PORT 0 4. Which of the ports act as the 16 bit address lines for transferring data through it? a) PORT 0 and PORT 1 b) PORT 1 and PORT 2 c) PORT 0 and PORT 2 d) PORT 1 and PORT 3 Answer: PORT 0 and PORT 2 5. Which instruction is used to check the status of a single bit? a) MOV A,P0 b) ADD A,#05H c) JNB PO.0, label d) CLR P0.05H Answer: JNB PO.0, label 6. Which of the following registers are not bit addressable? a) SCON b) PCON c) A d) PSW An

Multiple Choice Questions & Answers on 8051 Microcontroller Interrupt Programming 1. Which pin of the external hardware is said to exhibit INT0 interrupt? a) pin no 10 b) pin no 11 c) pin no 12 d) pin no 13 Answer: pin no 12 2. What are the contents of the IE register, when the interrupt of the memory location 0x00 is caused? a) 0xFFH b) 0x00H c) 0x10H d) 0xF0H Answer: 0x00H 3. Which of the following combination is the best to enable the external hardware interrupt 0 of the IE register (assuming initially all bits of the IE register are zero)? a) EX0=1 b) EA=1 c) any of the mentioned d) EX0=1 & EA=1 Answer: EX0=1 & EA=1. 4. Which bit of the IE register is used to enable TxD/RxD interrupt? a) IE.D5 b) IE.D2 c) IE.D3 d) IE.D4 Answer: IE.D4 5. What is the correct order of priority that is set after a controller gets reset? a) RI/TI > TF1 > TF0 > INT1 > INT0 b) RI/TI < TF1 < TF0 < INT1 < INT0 c) INT0 > TF0 > INT1 > TF1 > RI/TI d) INT0 < TF

Multiple Choice Questions & Answers on 8051 Microcontroller  Serial Port Communication 1. With what frequency UART operates( where f denoted the crystal frequency )? a) f/12 b) f/32 c) f/144 d) f/384 Answer: f/384 2. What is a null modem connection? a) no data transmission b) no MAX232 c) the RxD of one is the TxD for the other d) no serial communication Answer: the RxD of one is the TxD for the other 3. What should be done if we want to double the baud rate? a) change a bit of the TMOD register b) change a bit of the PCON register c) change a bit of the SCON register d) change a bit of the SBUF register Answer: change a bit of the PCON register 4. Which of the following signal control the flow of data? a) RTS b) DTR c) RTS & DTR d) None of the mentioned Answer: RTS 5. Which of the following best describes the use of framing in asynchronous means of communication? a) it binds the data properly b) it tells us about the start and stops of the data to be transmitted or received c)

Multiple Choice Questions & Answers on 8051 Microcontroller LCD and Keyboard Interfacing 1. The RS pin is _________ for an LCD. a) input b) output c) input & output d) none of the mentioned Answer: input 2. How many data lines are there in a 16*2 alphanumeric LCD? a) 16 b) 8 c) 1 d) 0 Answer: 8 3. In reading the columns of a matrix, if no key is pressed we should get all in binary notation a) 0 b) 1 c) F d) 7 Answer: 1 4. Which pin of the LCD is used for adjusting its contrast? a) pin no 1 b) pin no 2 c) pin no 3 d) pin no 4 Answer: pin no 3 5. How many rows and columns are present in a 16*2 alphanumeric LCD? a) rows=2, columns=32 b) rows=16, columns=2 c) rows=16, columns=16 d) rows=2, columns=16 Answer: rows=2, columns=16 6. Which command is used to select the 2 lines and 5*7 matrix of an LCD? a) 0x01 b) 0x06 c) 0x0e d) 0x38 Answer: 0x38 7. Which instruction is used to select the first row first column of an LCD? a) 0x08 b) 0x0c c) 0x80 d) 0xc0 Answer: 0x80 8. Which command of

Multiple Choice Questions & Answers on 8051Microcontroller ADC, DAC Interfacing 1. 8 input DAC has ________ a) 8 discrete voltage levels b) 64 discrete voltage levels c) 124 discrete voltage levels d) 256 discrete voltage levels Answer: 256 discrete voltage levels 2. What is the function of the WR pin? a) its active high input used to inform ADC0804 to the end of conversion b) its active low input used to inform ADC0804 to the end of conversion c) its active low input used to inform ADC0804 to the start of conversion d) its active high input used to inform ADC0804 to the start of conversion Answer: its active low input used to inform ADC0804 to the start of conversion 3. State which of the following statements are false? a) CLK IN pin used for External Clock Input or Internal Clock with external RC element b) INTR pin tells about the end of the conversion c) ADC0804 IC is an 8 bit parallel ADC in the family of the ADC0800 series d) None of the mentioned Answer: None of the mentio

Multiple Choice Questions & Answers on IOT Microcontroller Multiple Choice Questions & Answers on IOT Microcontroller ARM 7 1. ARM stands for _________ a) Advanced RISC Machine b) Advanced RISC Methadology c) Advanced Reduced Machine d) Advanced Reduced Methadology Answer: Advanced RISC Machine 2. The ARM7TDMI-S processor has __________ types of memory cycle. a) 5 b) 3 c) 4 d) 2 Answer: 4 3. _______ pin can be used to extend memory access in whole cycle increments. a) BTRAN b) BLOK c) BWAIT d) BCLK Answer: BWAIT 4. How many DC-DC converters interfaces in ARM7100? a) 5 b) 3 c) 4 d) 2 Answer: 2 5. What is the cache memory for ARM710T? a) 12Kb b) 16Kb c) 32Kb d) 8Kb Answer: 8Kb 6. What is the flash memory for LPC2141? a) 34kB b) 32kB c) 128kB d) 256kB Answer: 32kB 7. What is the size of ADC and DAC? a) 16 bit b) 10 bit c) 8 bit d) 32 bit Answer: 10 bit 8. What is the instruction set used by ARM7? a) 16-bit instruction set b) 32-bit instruction set c) 64-bit instruction set d) 8-bi

  Top 8051 Microcontroller Interview Questions And Answers      1. What is 8051 Microcontroller ? Answer: The Intel 8051 microcontroller is one of the most popular general-purpose microcontrollers in use today. It is an 8-bit family of microcontroller developed by Intel in the year 1981. This microcontroller was also referred to as “system on a chip” because it has 128 bytes of RAM, 4Kbytes of ROM, 2 Timers, 1 Serial port, and four ports on a single chip. 8051 microcontroller allows CPU to work on 8bits of data at a time.n case the data is larger than 8 bits then it has to be broken into parts so that the CPU can process conveniently. 2. What are applications of 8051 microcontrollers? Answer: The constant growth in information technology has provided many benefits of making use of a microcontroller, integrated circuits, embedded chips, microprocessors, etc. With these technologies, work is done faster and complexity is reduced. The 88051 microcontrollers are used in electronic and

Embedded System Design Introduction to Microcontrollers & Embedded processors   Introduction to Microcontrollers 1. In 8086 microprocessor , the address bus is ________ bit wide  10 bit  20 bit  16 bit  12 bit   Answer 20 bit 2. What is the file extension is used to load in a microcontroller to execute an instruction?  .doc  .c  .txt  .hex Answer .hex 3. What are the two instruction set architecture (ISA) classifications?  SIDC & BIDC  CISC & RISC  CISC & VISC Answer CISC & RISC 4. What is internal RAM memory of 8051 microprocessor?  32 bytes  64 bytes  128 bytes  256 bytes Answer 128 bytes 5. How many timers/counter 8051 16-bit microprocessor have?  1  2  5  8 Answer 2 timers/counter 6. Register that is used to holds the memory address of the next instruction to be executed is  Program Memory  Program Counter  Control Unit  Instruction decoder Answer Program Counter 7. The 8051 microprocessor has ________ parallel I/O ports.  2  3  4  5 Answer  4 parallel I/O ports