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. The speed of the microcontrollers is relatively slow compared to microprocessors. The microcontrollers are classified into three types based on bits they are 8 bit, 16 bit, and 32-bit microcontrollers. The 8-bit microcontrollers are used to execute both arithmetic and logical operations, the 8051 and 8031 are examples of 8-bit registers. The microcontrollers are of two types based on instruction set they are Reduced Instruction Set Computer, and Complex Instruction Set Computer.1). The microcontrollers are used in ____________ Computers, laptops, televisions Printers, refrigerators Microwave owens All of the above HintThe microcontrollers used in almost all electronic devices in order to control the operations of the devices. Examples: cameras, laptops, etc Read more about 8051 Microcontroller2). The speed of the microcontrollers are ___________ High Slow Very high Better HintThe speed of the microcontrollers are relatively slow compared to microprocessors3). How many of microcontrollers are there based on bits? One Two Three Four HintThe microcontrollers are classified into three types based on bits they are 8 bit, 16 bit, and 32-bit microcontrollers4). The microcontrollers based on memory classified into ______ 8 bit, 16 bit, 32 bit Embedded memory, external memory RISC, CISC All of the above HintThe microcontrollers are classified into two types based on memory they are embedded memory and external memory5). How many of microcontrollers are there based on instruction set? One Two Three Four HintThe microcontrollers are of two types based on instruction set they are Reduced Instruction Set Computer, and Complex Instruction Set Computer6). The 8-bit microcontrollers are used to execute _________ Arithmetic operations only Logical operations only Both a and b None of the above HintThe 8-bit microcontrollers are used to execute both arithmetic and logical operations, the 8051 and 8031 are examples of 8-bit registers7). ____________ is an example of 16 bit microcontroller 8031 microcontroller 8051 microcontroller 8096 microcontroller None of the above HintThe 8096 microcontroller is an example of a 16-bit microcontroller8). The 32 bit microcontroller used in automatically controlled applications like __________ Automatic operational machines Medical appliances Both a and b None of the above HintThe 32-bit microcontroller used in both automatic operational machines and medical appliances, etc9). 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 microcontroller Embedded memory microcontroller Both a and b None of the above HintThe external type of microcontroller is designed in such a way that it won't have a program memory on the chip10). _________ is an example of external memory microcontroller Intel 8031 microcontroller 8051 microcontroller 8096 microcontroller None of the above HintThe Intel 8031 microcontroller is an example of an external memory microcontroller11). In embedded memory microcontroller has __________ Programs, data Counters, timers Input/Output ports All of the above HintThe embedded type of microcontroller designed in such a way that microcontroller has all programs, data, counters, timers, I/O ports on the same chip12). __________ is an example of embedded memory microcontroller Intel 8031 microcontroller 8051 microcontroller 8096 microcontroller None of the above HintThe 8051 microcontroller is an example of an embedded memory microcontroller13). ___________ instruction set allows the user to insert a single instruction as an alternative to many simple instructions Reduced instruction set computer Complex instruction set computer Both a and b None of the above HintThe complex instruction set computer allows the user to insert a single instruction as an alternative to many simple instructions14). The reduced instruction set computer reduces the operational time by shortening the clock cycle per instruction True False HintYes, it is true the RISC reduces the operational time by shortening the clock cycle per instruction15). _____________ is the first microcontroller designed by intel Intel 8031 microcontroller 8051 microcontroller 8096 microcontroller None of the above HintThe 8051 microcontroller is the first microcontroller designed by intel16). The 8051 microcontroller is a __________ bit microcontroller 8 bit microcontroller 16 bit microcontroller 32 bit microcontroller None of the above HintThe 8051is an 8-bit microcontroller, which means it can read, write, and process only 8-bit data17). The microcontroller which will be dealing with 8 bit data that will be called as _________ 8 bit microcontroller 16 bit microcontroller 32 bit microcontroller None of the above HintThe microcontroller which will be dealing with 8-bit data that will be called an 8-bit microcontroller18). The microcontrollers are divided into how many categories? One Two Three Four HintThe microcontrollers are divided into three categories they are based on memory, based on bits, and based on instruction sets19). The 8051 microcontroller has______ 8 bit data bus 16 bit data bus 32 bit data bus None of the above HintThe 8051 microcontroller has an 8-bit data bus that is used to carry the data20). The 8051 microcontroller has______ 8 bit address bus 16 bit address bus 32 bit address bus None of the above HintThe 8051 microcontroller has a 16-bit address bus that is used to carry the addressesMicrocontrollers Quiz Questions and Answers21). The ALU performs ______________ Arithmetic operations only Logical operations only Both a and b None of the above HintThe ALU performs both arithmetic and logical operations and manipulates one bit as well as 8-bit data types22). The accumulator in an 8051 microcontroller is a ________ 8 bit register 16 bit register 32 bit register None of the above HintThe 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 operations23). What is the standard form of PSM? Program State Word Program Status Word Program Single Word None of the above HintThe standard form of PSM is Program Status Word, which shows the status of all the flags of the 8051 microcontroller24). The stack pointer in 8051 architecture is a ________ 8 bit register 16 bit register 32 bit register None of the above HintThe stack pointer in 8051 architecture is a 16-bit register which is pointing towards the starting address of the stack25). The data pointer in an 8051 architecture is a __________ 8 bit register 16 bit register 32 bit register None of the above HintThe data pointer in an 8051 architecture is a 16-bit register that is used to hold the 16-bit address of the data memory26). _____________is used as address pointer in order to access the instructions of the program Stack pointer Program Counter Data pointer None of the above HintThe program counter is used as an address pointer in order to access the instructions of the program27). The microcontroller has only one or two instructions to move data between memory and CPU True False HintYes, it is true the MC has only one or two instructions to move data between memory and CPU whereas the microprocessor has many instructions28). How many bit handling instructions does microcontroller have? One Two Three None of the above HintThe microcontroller has many bit handling instructions whereas the microprocessor has one or two-bit handling instructions29). The access time for built in memory and input/output devices in microcontroller is ____ High Very high Less Better HintThe access time for built-in memory and input/output devices in the microcontroller is less30). The microcontroller requires less hardware devices True False HintThe microcontroller requires fewer hardware devices because all the devices present on the same chip31). In microcontroller power consumption is _______ High Very high Less Better HintIn microcontroller power consumption is less because the microcontrollers are developed by using CMOS technology 32). The 8051 instructions divided into how many categories? Three Four Five Six HintThe 8051 instructions divided into six categories they are data transfer, logical, arithmetic, branch, subroutine, and bit manipulation instruction33). _________ instruction move the contents of a register to accumulator MOV instruction PUSH and POP XCHG instruction None of the above HintThe MOV instruction moves the contents of a register to the accumulator34). ________ defines the byte type variable EQU (equate) DB (define byte) ASCII None of the above HintThe DB (define byte) defines the byte type variable35). When define byte assembly directive used to define data the numbers can be in _______ Decimal format Binary format Hex or ASCII format All of the above HintWhen defining byte assembly directive used to define data the numbers can be in decimal format, binary format, and hexadecimal or ASCII format36). The assembler always converts number (byte) to _______ format Decimal format Binary format Hexa decimal format All of the above HintThe assembler always converts the number (byte) to hexadecimal format37). Which assembler directive is used to set the beginning address of the program? ORG (orginate) EQU (equate) DB (define byte) All of the above HintThe ORG (originate) assembler directive is used to set the beginning address of the program38). How many bit handling instructions does microprocessor have? One Two One or two None of the above HintThe microprocessor has one or two-bit handling instructions whereas microcontroller has many bit handling instructions39). The MOV instruction, push pop instruction, XCHG instruction comes under ___________ Arithematic instruction Data transfer instruction Bit manipulation instruction Branch instruction HintThe MOV instruction, push pop instruction, XCHG instruction comes under data transfer instruction40). In __________ the characters are placed in quotation marks Add description here! Decimal format Binary format ASCII format None of the above HintIn ASCII format the characters are placed in quotation marksMicrocontrollers Important Questions and Answers41). The assembler directive _______ is placed at the end of the source and it acts as the last statement of the program ORG (orginate) EQU (equate) DB (define byte) END HintThe assembler directive END is placed at the end of the source and it acts as the last statement of the program42). ________ declare 24 byte stack in data segment that starts at internal RAM location 08H DS (Data Segment) DB (Define Byte) ORG (orginate) None of the above HintThe data segment declare a 24-byte stack in the data segment that starts at internal RAM location 08H43). __________ assembler directive declares the variables defined in a specific file that ca be used in the other source file Public assembler directive Data segment assembler directive Extern assembler directive END assembler directive HintThe public assembler directive declares the variables defined in a specific file that can be used in the other source file44). ____________ assembler directive declares the variables that are used in the present file but are defined in some other source file Public assembler directive Data segment assembler directive Extern assembler directive END assembler directive HintThe extern assembler directive declares the variables that are used in the present file but are defined in some other source file45). 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 PC POP the current stack top to PCW Both a and b None of the above HintWhen the return instruction is executed it is going to pop the current stack top to PC and then pop the current stack top to PCW46). The interrupts in 8051 microcontroller are classified into __________ Two types Three types Four types Five types HintThe interrupts in the 8051 microcontrollers are classified into three types they are external and internal, maskable and nonmaskable, and vectored and non vectored interrupts47). How many external interrupts does 8051 microcontroller have? Two Three Four Five HintThere are two external interrupts in the 8051 microcontrollers they are external interrupt 0 and external interrupt 148). If any internal peripheral generating an interrupt request that will be called an _________ External interrupt Internal interrupt Vectored interrupt None of the above HintIf any internal peripheral generating an interrupt request that will be called an internal interrupt49). If any external peripheral generating an external request that will be called an _________ External interrupt Internal interrupt Vectored interrupt None of the above HintIf any external peripheral generating an interrupt request that will be called an external interrupt50). The interrupts which can be disabled by the microcontroller using some instructions is called as _________ External interrupt Internal interrupt Vectored interrupt Non maskable interrupts HintThe interrupts which can be disabled by the microcontroller using some instructions are called nonmaskable interrupts51). If the address provided by some peripheral devices that type of interrupts are called as __________ External interrupt Internal interrupt Non vectored interrupt Non maskable interrupts HintIf the address provided by some peripheral devices that type of interrupts are called as non vectored interrupt52). In ___________ interrupts the starting address is fixed External interrupt Vectored interrupts Non vectored interrupt Non maskable interrupts HintIn vectored interrupts the starting address is predefined53). How many interrupts are available in 8051 microcontroller? Two Three Four Five HintFive interrupts are available in the 8051 microcontrollers, out of five three are internal interrupts and the remaining two are external interrupts54). The 8051 microcontroller has five interrupts and the five interrupts are _________ External interrupt Maskable interrupt Vectored interrupts Both b and c HintThe 8051 microcontroller has five interrupts and the five interrupts are maskable and vectored interrupts55). What are the five interrupts of 8051 microcontroller? External interrupt 0, external interrupt 1 Internal interrupt 0, internal interrupt 1 Timer 0 interrupt, timer 1 interrupt All of the above HintThe five interrupts of the 8051 microcontrollers are external interrupt 0 and 1, internal interrupt 0 and 1, and timer interrupt 0 and 156). __________ interrupts are the internal interrupts in 8051 microcontroller External interrupt 0, external interrupt 1 Serial interrupt Timer 0 interrupt, timer 1 interrupt Both b and c HintThe serial interrupt, the timer interrupt 0, and timer interrupt 1 is the internal interrupts in the 8051 microcontroller57). The interrupt enable and interrupt priority registers in 8051 microcontroller is a ______ 8 bit register 16 bit register 32 bit register None of the above HintThe interrupt enable and interrupt priority registers in the 8051 microcontrollers are 8-bit registers58). How many oscillator periods defines the machine cycle 2 oscillator periods 4 oscillator periods 6 oscillator periods 12 oscillator periods Hint12 oscillator periods define the machine cycle59). How many states does machine cycle consists of ______ Two states Four states Six states Twelve states HintThe machine cycle consists of 12 states and each state lasts for two oscillator clock periods60). In reduced instruction set computer architecture the number of instructions involved is _______ High Less Better Very high HintIn reduced instruction set computer architecture the number of instructions involved is less and the instructions are also very simpleMicrocontrollers Interview Questions and Answers61). In complex instruction set computer architecture the number of instructions involved is _______ More Less Better Very less HintIn complex instruction set computer architecture the number of instructions involved is more and the instructions are not simple62). The small computer instructions provide _______ to the processors High speed Low speed Very low speed Very high speed HintThe small computer instructions provide high speed to the processors, due to high speed they can perform millions of instructions per sec63). The applications of ARM processor are ______ Smart phones Multimedia players Tabs All of the above HintThe ARM processors are extensively used in consumer electronic devices example smartphones, tablets, multimedia players, etc Read more about ARM Processor64). The ARM processors are _______ Smaller in size Consumes less power Reduced complexity All of the above HintThe 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 reduced65). The serial data communication in 8051 microcontroller uses ________ a) Synchronous method Asynchronous method Both synchronous and asynchronous method None of the above HintThe serial data communication in 8051 microcontroller uses both synchronous and asynchronous method66). What is the standard form of UART? Universal Asynchronous Synchronous Receiver Transmitter Universal Synchronous Receiver Transmitter Universal Asynchronous Receiver Transmitter None of the above HintThe 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 Transmitter Universal Synchronous Receiver Transmitter Universal Asynchronous Receiver Transmitter Universal Synchronous Asynchronous Receiver Transmitter HintThe standard form of USART is Universal Synchronous Asynchronous Receiver Transmitter68). In which duplex the data is transmitted in one way at a time? Full-duplex Half-duplex Simplex None of the above HintIn half-duplex, the data is transmitted in one way at a time69). In which duplex the data is transmitted in both ways at the same time? Full-duplex Half-duplex Simplex None of the above HintIn full-duplex the data is transmitted in both ways at the same time70). The serial control register (SCON register) operates in how many modes? One mode Two modes Three modes Four modes HintThe serial control register (SCON register) operates in four modes they are mode0, mode1, mode2, and mode371). The vector address of the timer interrupt 1 is ________ 000B 0003 001B None of the above HintThe vector address of the timer interrupt 1 is 001B72). The mode 1 in the serial control register (SCON) is a ______ 8 bit UART with timer data rate 9 bit UART with set data rate 9 bit UART with timer data rate Synchronous serial communication HintMode 1 in the serial control register is an 8 bit UART with a timer data rate73). The mode 2 in the serial control register (SCON) is a ______ with set data rate 8 bit UART 9 bit UART 9 bit USART Synchronous serial communication HintMode 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 rate 9 bit UART with set data rate 9 bit UART with timer data rate Synchronous serial communication HintMode 3 in the serial control register is a 9 bit UART with a timer data rate75). What is the standard of the SBUF register? Serial buffer register Parallel buffer register Standard buffer register None of the above HintThe standard of SBUF register is serial buffer register, it is one type of register related to serial communication76). The serial buffer register is an ______ 8 bit register 16 bit register 32 bit register None of the above HintThe serial buffer register is an 8-bit register used for serial communication77). How many transistors do small scale integration IC’s require? <10 transistors 10-100 transistors 100-10k transistors 10k transistors HintThe small scale integration IC’s has less than 10 transistors on a single IC78). How many transistors do medium scale integration IC’s require? <10 transistors 10-100 transistors 100-10k transistors 10k transistors HintThe medium-scale integration IC’s has less than 10-100 transistors on a single IC79). How many transistors do large-scale integration IC’s require? <10 transistors 10-100 transistors 100-10k transistors 10k transistors HintThe large scale integration IC’s has less than 100-10k transistors on a single IC80). How many transistors do very large-scale integration IC’s require? <10 transistors 10-100 transistors 100-10k transistors 10k transistors HintThe very large scale integration IC’s has less than10k transistors on a single ICMicrocontrollers Questions and Answers for Engineers81). Which one is the bit addressable register? SBUF PCON SCON TMOD HintThe SCON is the bit addressable register82). Which of the following is an 8 bit register? Program status word, Timer control register Accumulator Both a and b None of the above HintThe program status word, accumulator, and timer control registers all are 8-bit registers83). Which register provides the status and control information about the serial port is _________ Only SCON Only PCON TSCON PCON & SCON HintThe PCON and SCON registers provide the control and status information about the serial port84). Which register provides control and status information about counters is ________ Only SCON TMOD Only TSCON PCON and SCON HintThe register that provides control and status information about counters is TMOD85). The receive buffer of the serial data buffer is a_______ Serial in parallel out register Serial in serial out register Parallel in parallel out register Parallel in serial out register HintThe receive buffer of the serial data buffer is a serial in parallel out register86). Which register contains the status information? Control registers Instruction registers Program status word PCON and SCON HintThe registers that contain the status information is program status word87). Which register used as a scratchpad? B registers Instruction registers Program status word Status registers HintThe B register is used as a scratchpad88). Which register used as an operand register? Accumulator Instruction registers Program status word Accumulator and B register HintThe register that may be used as an operand register is the accumulator and the B register89). Which register is used for accessing the external data memory? LDPTR DPTRL DPTR None of the above HintThe DPTR register is used for accessing the external data memory 90). The vector address of the external interrupt 0 is ________ 000B 0003 001B None of the above HintThe vector address of the external interrupt 0 is 000391). The vector address of the external interrupt 1 is ________ 000B 0003 0013 None of the above HintThe vector address of the external interrupt 1 is 0013 Time is Up! Time's up
