Microcontrollers Question & AnswersJune 5, 2021 By WatElectronics This article lists 90+ Microcontrollers MCQs for engineering students. All the Microcontrollers Questions & Answers given below include a solution and link wherever possible to the relevant topic.The microcontrollers used in almost all electronic devices, it is composed of two terms micro and controller, whereas micro means very small in size, and controller means a device that controls the operations of all the devices. The microcontroller consists of various components like memory, serial input/output ports, peripheral devices, timers, counters, and clock circuits, so the microcontroller is nothing but an on-chip computer where all the devices of the computer are embedded on a single chip. It can be used as an engine controller in automobiles, they are also used in washing machines, refrigerators, microwave ovens for controlling the temperature in the ovens, etc. 1). The microcontrollers are used in ____________Computers, laptops, televisionsPrinters, refrigeratorsMicrowave owensAll of the aboveHintThe microcontrollers used in almost all electronic devices in order to control the operations of the devices. Examples: cameras, laptops, etc Read more about 8051 Microcontroller 2). The speed of the microcontrollers are ___________HighSlowVery highBetterHintThe speed of the microcontrollers are relatively slow compared to microprocessors 3). How many of microcontrollers are there based on bits?OneTwoThreeFourHintThe microcontrollers are classified into three types based on bits they are 8 bit, 16 bit, and 32-bit microcontrollers 4). The microcontrollers based on memory classified into ______8 bit, 16 bit, 32 bitEmbedded memory, external memoryRISC, CISCAll of the aboveHintThe microcontrollers are classified into two types based on memory they are embedded memory and external memory 5). How many of microcontrollers are there based on instruction set?OneTwoThreeFourHintThe microcontrollers are of two types based on instruction set they are Reduced Instruction Set Computer, and Complex Instruction Set Computer 6). The 8-bit microcontrollers are used to execute _________Arithmetic operations onlyLogical operations onlyBoth a and bNone of the aboveHintThe 8-bit microcontrollers are used to execute both arithmetic and logical operations, the 8051 and 8031 are examples of 8-bit registers 7). ____________ is an example of 16 bit microcontroller8031 microcontroller8051 microcontroller8096 microcontrollerNone of the aboveHintThe 8096 microcontroller is an example of a 16-bit microcontroller 8). The 32 bit microcontroller used in automatically controlled applications like __________Automatic operational machinesMedical appliancesBoth a and bNone of the aboveHintThe 32-bit microcontroller used in both automatic operational machines and medical appliances, etc 9). The type of microcontroller is designed in such a way that they don’t have a program memory on the chip is called as __________External memory microcontrollerEmbedded memory microcontrollerBoth a and bNone of the aboveHintThe external type of microcontroller is designed in such a way that it won't have a program memory on the chip 10). _________ is an example of external memory microcontrollerIntel 8031 microcontroller8051 microcontroller8096 microcontrollerNone of the aboveHintThe Intel 8031 microcontroller is an example of an external memory microcontroller 11). In embedded memory microcontroller has __________Programs, dataCounters, timersInput/Output portsAll of the aboveHintThe embedded type of microcontroller designed in such a way that microcontroller has all programs, data, counters, timers, I/O ports on the same chip 12). __________ is an example of embedded memory microcontrollerIntel 8031 microcontroller8051 microcontroller8096 microcontrollerNone of the aboveHintThe 8051 microcontroller is an example of an embedded memory microcontroller 13). ___________ instruction set allows the user to insert a single instruction as an alternative to many simple instructionsReduced instruction set computerComplex instruction set computerBoth a and bNone of the aboveHintThe complex instruction set computer allows the user to insert a single instruction as an alternative to many simple instructions 14). The reduced instruction set computer reduces the operational time by shortening the clock cycle per instructionTrueFalseHintYes, it is true the RISC reduces the operational time by shortening the clock cycle per instruction 15). _____________ is the first microcontroller designed by intelIntel 8031 microcontroller8051 microcontroller8096 microcontrollerNone of the aboveHintThe 8051 microcontroller is the first microcontroller designed by intel 16). The 8051 microcontroller is a __________ bit microcontroller8 bit microcontroller16 bit microcontroller32 bit microcontrollerNone of the aboveHintThe 8051is an 8-bit microcontroller, which means it can read, write, and process only 8-bit data 17). The microcontroller which will be dealing with 8 bit data that will be called as _________8 bit microcontroller16 bit microcontroller32 bit microcontrollerNone of the aboveHintThe microcontroller which will be dealing with 8-bit data that will be called an 8-bit microcontroller 18). The microcontrollers are divided into how many categories?OneTwoThreeFourHintThe microcontrollers are divided into three categories they are based on memory, based on bits, and based on instruction sets 19). The 8051 microcontroller has______8 bit data bus16 bit data bus32 bit data busNone of the aboveHintThe 8051 microcontroller has an 8-bit data bus that is used to carry the data 20). The 8051 microcontroller has______8 bit address bus16 bit address bus32 bit address busNone of the aboveHintThe 8051 microcontroller has a 16-bit address bus that is used to carry the addressesMicrocontrollers Quiz Questions and Answers 21). The ALU performs ______________Arithmetic operations onlyLogical operations onlyBoth a and bNone of the aboveHintThe ALU performs both arithmetic and logical operations and manipulates one bit as well as 8-bit data types 22). The accumulator in an 8051 microcontroller is a ________8 bit register16 bit register32 bit registerNone of the aboveHintThe accumulator in an 8051 microcontroller is an 8-bit register and it is used to hold the data and receive the result of the ALU operations 23). What is the standard form of PSM?Program State WordProgram Status WordProgram Single WordNone of the aboveHintThe standard form of PSM is Program Status Word, which shows the status of all the flags of the 8051 microcontroller 24). The stack pointer in 8051 architecture is a ________8 bit register16 bit register32 bit registerNone of the aboveHintThe stack pointer in 8051 architecture is a 16-bit register which is pointing towards the starting address of the stack 25). The data pointer in an 8051 architecture is a __________8 bit register16 bit register32 bit registerNone of the aboveHintThe data pointer in an 8051 architecture is a 16-bit register that is used to hold the 16-bit address of the data memory 26). _____________is used as address pointer in order to access the instructions of the programStack pointerProgram CounterData pointerNone of the aboveHintThe program counter is used as an address pointer in order to access the instructions of the program 27). The microcontroller has only one or two instructions to move data between memory and CPUTrueFalseHintYes, it is true the MC has only one or two instructions to move data between memory and CPU whereas the microprocessor has many instructions 28). How many bit handling instructions does microcontroller have?OneTwoThreeNone of the aboveHintThe microcontroller has many bit handling instructions whereas the microprocessor has one or two-bit handling instructions 29). The access time for built in memory and input/output devices in microcontroller is ____HighVery highLessBetterHintThe access time for built-in memory and input/output devices in the microcontroller is less 30). The microcontroller requires less hardware devicesTrueFalseHintThe microcontroller requires fewer hardware devices because all the devices present on the same chip 31). In microcontroller power consumption is _______HighVery highLessBetterHintIn microcontroller power consumption is less because the microcontrollers are developed by using CMOS technology 32). The 8051 instructions divided into how many categories?ThreeFourFiveSixHintThe 8051 instructions divided into six categories they are data transfer, logical, arithmetic, branch, subroutine, and bit manipulation instruction 33). _________ instruction move the contents of a register to accumulatorMOV instructionPUSH and POPXCHG instructionNone of the aboveHintThe MOV instruction moves the contents of a register to the accumulator 34). ________ defines the byte type variableEQU (equate)DB (define byte)ASCIINone of the aboveHintThe DB (define byte) defines the byte type variable 35). When define byte assembly directive used to define data the numbers can be in _______Decimal formatBinary formatHex or ASCII formatAll of the aboveHintWhen defining byte assembly directive used to define data the numbers can be in decimal format, binary format, and hexadecimal or ASCII format 36). The assembler always converts number (byte) to _______ formatDecimal formatBinary formatHexa decimal formatAll of the aboveHintThe assembler always converts the number (byte) to hexadecimal format 37). Which assembler directive is used to set the beginning address of the program?ORG (orginate)EQU (equate)DB (define byte)All of the aboveHintThe ORG (originate) assembler directive is used to set the beginning address of the program 38). How many bit handling instructions does microprocessor have?OneTwoOne or twoNone of the aboveHintThe microprocessor has one or two-bit handling instructions whereas microcontroller has many bit handling instructions 39). The MOV instruction, push pop instruction, XCHG instruction comes under ___________Arithematic instructionData transfer instructionBit manipulation instructionBranch instructionHintThe MOV instruction, push pop instruction, XCHG instruction comes under data transfer instruction 40). In __________ the characters are placed in quotation marksAdd description here!Decimal formatBinary formatASCII formatNone of the aboveHintIn ASCII format the characters are placed in quotation marksMicrocontrollers Important Questions and Answers 41). The assembler directive _______ is placed at the end of the source and it acts as the last statement of the programORG (orginate)EQU (equate)DB (define byte)ENDHintThe assembler directive END is placed at the end of the source and it acts as the last statement of the program 42). ________ declare 24 byte stack in data segment that starts at internal RAM location 08HDS (Data Segment)DB (Define Byte)ORG (orginate)None of the aboveHintThe data segment declare a 24-byte stack in the data segment that starts at internal RAM location 08H 43). __________ assembler directive declares the variables defined in a specific file that ca be used in the other source filePublic assembler directiveData segment assembler directiveExtern assembler directiveEND assembler directiveHintThe public assembler directive declares the variables defined in a specific file that can be used in the other source file 44). ____________ assembler directive declares the variables that are used in the present file but are defined in some other source filePublic assembler directiveData segment assembler directiveExtern assembler directiveEND assembler directiveHintThe extern assembler directive declares the variables that are used in the present file but are defined in some other source file 45). The interrupt service routine always ends with return (RET) instruction, and the execution of the RET instruction results in ____________POP the current stack top to PCPOP the current stack top to PCWBoth a and bNone of the aboveHintWhen the return instruction is executed it is going to pop the current stack top to PC and then pop the current stack top to PCW 46). The interrupts in 8051 microcontroller are classified into __________Two typesThree typesFour typesFive typesHintThe interrupts in the 8051 microcontrollers are classified into three types they are external and internal, maskable and nonmaskable, and vectored and non vectored interrupts 47). How many external interrupts does 8051 microcontroller have?TwoThreeFourFiveHintThere are two external interrupts in the 8051 microcontrollers they are external interrupt 0 and external interrupt 1 48). If any internal peripheral generating an interrupt request that will be called an _________External interruptInternal interruptVectored interruptNone of the aboveHintIf any internal peripheral generating an interrupt request that will be called an internal interrupt 49). If any external peripheral generating an external request that will be called an _________External interruptInternal interruptVectored interruptNone of the aboveHintIf any external peripheral generating an interrupt request that will be called an external interrupt 50). The interrupts which can be disabled by the microcontroller using some instructions is called as _________External interruptInternal interruptVectored interruptNon maskable interruptsHintThe interrupts which can be disabled by the microcontroller using some instructions are called nonmaskable interrupts 51). If the address provided by some peripheral devices that type of interrupts are called as __________External interruptInternal interruptNon vectored interruptNon maskable interruptsHintIf the address provided by some peripheral devices that type of interrupts are called as non vectored interrupt 52). In ___________ interrupts the starting address is fixedExternal interruptVectored interruptsNon vectored interruptNon maskable interruptsHintIn vectored interrupts the starting address is predefined 53). How many interrupts are available in 8051 microcontroller?TwoThreeFourFiveHintFive interrupts are available in the 8051 microcontrollers, out of five three are internal interrupts and the remaining two are external interrupts 54). The 8051 microcontroller has five interrupts and the five interrupts are _________External interruptMaskable interruptVectored interruptsBoth b and cHintThe 8051 microcontroller has five interrupts and the five interrupts are maskable and vectored interrupts 55). What are the five interrupts of 8051 microcontroller?External interrupt 0, external interrupt 1Internal interrupt 0, internal interrupt 1Timer 0 interrupt, timer 1 interruptAll of the aboveHintThe five interrupts of the 8051 microcontrollers are external interrupt 0 and 1, internal interrupt 0 and 1, and timer interrupt 0 and 1 56). __________ interrupts are the internal interrupts in 8051 microcontrollerExternal interrupt 0, external interrupt 1Serial interruptTimer 0 interrupt, timer 1 interruptBoth b and cHintThe serial interrupt, the timer interrupt 0, and timer interrupt 1 is the internal interrupts in the 8051 microcontroller 57). The interrupt enable and interrupt priority registers in 8051 microcontroller is a ______8 bit register16 bit register32 bit registerNone of the aboveHintThe interrupt enable and interrupt priority registers in the 8051 microcontrollers are 8-bit registers 58). How many oscillator periods defines the machine cycle2 oscillator periods4 oscillator periods6 oscillator periods12 oscillator periodsHint12 oscillator periods define the machine cycle 59). How many states does machine cycle consists of ______Two statesFour statesSix statesTwelve statesHintThe machine cycle consists of 12 states and each state lasts for two oscillator clock periods 60). In reduced instruction set computer architecture the number of instructions involved is _______HighLessBetterVery highHintIn reduced instruction set computer architecture the number of instructions involved is less and the instructions are also very simpleMicrocontrollers Interview Questions and Answers 61). In complex instruction set computer architecture the number of instructions involved is _______MoreLessBetterVery lessHintIn complex instruction set computer architecture the number of instructions involved is more and the instructions are not simple 62). The small computer instructions provide _______ to the processorsHigh speedLow speedVery low speedVery high speedHintThe small computer instructions provide high speed to the processors, due to high speed they can perform millions of instructions per sec 63). The applications of ARM processor are ______Smart phonesMultimedia playersTabsAll of the aboveHintThe ARM processors are extensively used in consumer electronic devices example smartphones, tablets, multimedia players, etc Read more about ARM Processor 64). The ARM processors are _______Smaller in sizeConsumes less powerReduced complexityAll of the aboveHintThe ARM processors are smaller in size as the size is small the power consumption will be less, if the instructions are less the complexity is reduced 65). The serial data communication in 8051 microcontroller uses ________a) Synchronous methodAsynchronous methodBoth synchronous and asynchronous methodNone of the aboveHintThe serial data communication in 8051 microcontroller uses both synchronous and asynchronous method 66). What is the standard form of UART?Universal Asynchronous Synchronous Receiver TransmitterUniversal Synchronous Receiver TransmitterUniversal Asynchronous Receiver TransmitterNone of the aboveHintThe standard form of UART is Universal Asynchronous Receiver Transmitter Read more about UART 67). What is the standard form of USART?Universal Asynchronous Synchronous Receiver TransmitterUniversal Synchronous Receiver TransmitterUniversal Asynchronous Receiver TransmitterUniversal Synchronous Asynchronous Receiver TransmitterHintThe standard form of USART is Universal Synchronous Asynchronous Receiver Transmitter 68). In which duplex the data is transmitted in one way at a time?Full-duplexHalf-duplexSimplexNone of the aboveHintIn half-duplex, the data is transmitted in one way at a time 69). In which duplex the data is transmitted in both ways at the same time?Full-duplexHalf-duplexSimplexNone of the aboveHintIn full-duplex the data is transmitted in both ways at the same time 70). The serial control register (SCON register) operates in how many modes?One modeTwo modesThree modesFour modesHintThe serial control register (SCON register) operates in four modes they are mode0, mode1, mode2, and mode3 71). The vector address of the timer interrupt 1 is ________000B0003001BNone of the aboveHintThe vector address of the timer interrupt 1 is 001B 72). The mode 1 in the serial control register (SCON) is a ______8 bit UART with timer data rate9 bit UART with set data rate9 bit UART with timer data rateSynchronous serial communicationHintMode 1 in the serial control register is an 8 bit UART with a timer data rate 73). The mode 2 in the serial control register (SCON) is a ______ with set data rate8 bit UART9 bit UART9 bit USARTSynchronous serial communicationHintMode 2 in the serial control register is a 9 bit UART with a set data rate 74). The mode 3 in the serial control register (SCON) is a ______8 bit UART with timer data rate9 bit UART with set data rate9 bit UART with timer data rateSynchronous serial communicationHintMode 3 in the serial control register is a 9 bit UART with a timer data rate 75). What is the standard of the SBUF register?Serial buffer registerParallel buffer registerStandard buffer registerNone of the aboveHintThe standard of SBUF register is serial buffer register, it is one type of register related to serial communication 76). The serial buffer register is an ______8 bit register16 bit register32 bit registerNone of the aboveHintThe serial buffer register is an 8-bit register used for serial communication 77). How many transistors do small scale integration IC’s require?<10 transistors10-100 transistors100-10k transistors10k transistorsHintThe small scale integration IC’s has less than 10 transistors on a single IC 78). How many transistors do medium scale integration IC’s require?<10 transistors10-100 transistors100-10k transistors10k transistorsHintThe medium-scale integration IC’s has less than 10-100 transistors on a single IC 79). How many transistors do large-scale integration IC’s require?<10 transistors10-100 transistors100-10k transistors10k transistorsHintThe large scale integration IC’s has less than 100-10k transistors on a single IC 80). How many transistors do very large-scale integration IC’s require?<10 transistors10-100 transistors100-10k transistors10k transistorsHintThe very large scale integration IC’s has less than10k transistors on a single ICMicrocontrollers Questions and Answers for Engineers 81). Which one is the bit addressable register?SBUFPCONSCONTMODHintThe SCON is the bit addressable register 82). Which of the following is an 8 bit register?Program status word, Timer control registerAccumulatorBoth a and bNone of the aboveHintThe program status word, accumulator, and timer control registers all are 8-bit registers 83). Which register provides the status and control information about the serial port is _________Only SCONOnly PCONTSCONPCON & SCONHintThe PCON and SCON registers provide the control and status information about the serial port 84). Which register provides control and status information about counters is ________Only SCONTMODOnly TSCONPCON and SCONHintThe register that provides control and status information about counters is TMOD 85). The receive buffer of the serial data buffer is a_______Serial in parallel out registerSerial in serial out registerParallel in parallel out registerParallel in serial out registerHintThe receive buffer of the serial data buffer is a serial in parallel out register 86). Which register contains the status information?Control registersInstruction registersProgram status wordPCON and SCONHintThe registers that contain the status information is program status word 87). Which register used as a scratchpad?B registersInstruction registersProgram status wordStatus registersHintThe B register is used as a scratchpad 88). Which register used as an operand register?AccumulatorInstruction registersProgram status wordAccumulator and B registerHintThe register that may be used as an operand register is the accumulator and the B register 89). Which register is used for accessing the external data memory?LDPTRDPTRLDPTRNone of the aboveHintThe DPTR register is used for accessing the external data memory 90). The vector address of the external interrupt 0 is ________000B0003001BNone of the aboveHintThe vector address of the external interrupt 0 is 0003 91). The vector address of the external interrupt 1 is ________000B00030013None of the aboveHintThe vector address of the external interrupt 1 is 0013 Time is Up!
