8085 Microprocessor Question & AnswersOctober 11, 2021 By WatElectronics This article lists 100+ 8085 Microprocessor MCQs for engineering students. All the 8085 Microprocessor Questions & Answers given below include a hint and a link wherever possible to the relevant topic. This is helpful for users who are preparing for their exams, interviews, or professionals who would like to brush up their fundamentals on 8085 Microprocessor8085 Microprocessor is an 8-bit programmable IC or integrated circuit invented by Intel in the year 1977. This microprocessor uses NMOS technology and it is pronounced “eighty-eighty-five” microprocessor. This microprocessor has the capabilities of decision-making & computing like the CPU of a personal computer. The configuration of 8085 is available with data bus - 8-bit, address bus - 16-bit, a 16-bit based program counter (PC), stack pointer -16-bit, 8-bit registers - 6 which are arranged in BC, HL & DE pairs and needs 5V supply at 3.2 MHZ 1-phase CLK.The functional unit 8085 microprocessor includes ALU, accumulator, the program counter (PC), the stack pointer (SP), general-purpose register, flag register, temporary register, address bus, data bus, interrupt control, serial I/O control, etc. The applications of the 8085 microprocessor include almost all electronic devices which include printers, mobiles, washing machines, and also in superior applications such as flights, satellites, radars, etc.1). How many pins of 8085 microprocessor includes? 40 35 28 64 HintIt includes above 35 pins2). How many output pins an 8085 microprocessor includes? 40 19 27 21 HintIt ranges from < 25 > 303). The 8085 microprocessor program counter or PC is a 16-bit register, for the reason that? At a time it calculates 16-bits Address lines are 16 It helps the user in storing 16-bit data for the time being At a time it has to obtain two 8-bit data HintIt includes sixteen address lines 4). In 8085A Intel microprocessor, the signal of an ALE signal is finished high to...? Allow the data bus to be utilized like a low order address bus To handle D0-D7 data from the data bus To immobilize data bus To get all the above functions HintHere data bus is used as a less order data bus5). Which of the following is the first machine cycle instruction for an 8085 Intel microprocessor. Write cycle for a memory Operation code for fetch cycle Read cycle for a memory Input/output read cycle HintIt is also known as op-code.6). What is the function of the READY signal in an 8085 microprocessor? To specify to the user that 8085 is working properly as well as is ready for utilize To offer appropriate WAIT states as the 8085 is conversing by a slow peripheral device To slow down a quick device for communicating at the device of microprocessor None of these HintThis is an active high i/p control signal7). Which of the following flag is present in the 8085 microprocessor? Sign flag Trap flag Parity flag Auxiliary carry flag HintIt allows the operation of processors within single step condition8). The ALU of 8085 microprocessor includes? Accumulator, short-term register, arithmetic & logic circuits Arithmetic, Accumulator, logic circuits & 5 flags Accumulator, short-term register, logic circuits, arithmetic, & 5 five flags Accumulator, arithmetic & logic circuits HintMaximum all the components9). Which of the following 16-bit register is for 8085? Accumulator Register C Stack pointer Register HintIt is used to store 8-bit data10). What are the DMA signals for 8085 microprocessors? READY HOLD HLDA All of the above HintIt transfers the data directly without any interrupt of the CPU11). What kind of interrupts are RST0 to RST7 in the 8085 microprocessor? Logical interrupts Hardware interrupts Conditional interrupts Software interrupts HintIt causes through a special instruction within the instruction set12). Which of the following interrupt is non-vectored in 8085? RST 5.5 TRAP INTR RST 7 HintIt is a maskable interrupt13). The segments of 8085 microprocessor includes? 4 3 2 1 HintIt includes >3 < 5 segments14). Which of the following microprocessor includes virtual memory in the family of Intel microprocessors? Pentium 80386 80286 80486 HintIt is a 16-bit microprocessor 15). How many maskable interrupts are available in the 8085 microprocessor? 1 4 6 8 HintIt ranges from > 3 < 516). Which of the following STACK is used in 8085? LIFO FIFO LILO FILO HintIts full form is last in first out17). How many bytes are present in the 8085 instruction 1 or 2 1, 2 or 3 Only 1 2 or 3 HintMinimum two otherwise 318). The addressing technique which is not used in 8085? Register Relative Immediate Indirect Register HintThis addressing is available in bytes only19). Which of the following register is not used in the 8085 programming model? Instruction Status Memory address Temporary Data HintIt includes the data regarding the state of the microprocessor20). Consider the below registers like 1). Accumulator & flag register2). Registers B & C 3). Registers D &E 4). Registers H & LAnd which of the above registers can be coupled jointly for making a 16-bit register? 1, 3 & 4 1, 2 & 3 2, 3 & 4 1, 2 & 4 HintThey are B,D, C,H, L, E21). The maskable interrupts in 8085 microprocessor are? 2 4 6 8 HintThey are INTR, RST 6.5, 5.5 & 7.522). Which of the following stack is used in 8085? LIFO FIFO LILO FILO HintIt is also known as last in first out23). In the 8085 instruction set, how many bytes are present? 1 or 2 1 or 2 or 3 2 4 HintThe bits present in the instruction set are a minimum 1 maximum of 324). In 8085, which of the following addressing method is not used? Immediate Relative Register indirect Register HintIn this method, the operand’s Effective Address is calculated.25). Which of the below register is not used in the programming of 8085? Instruction Status Memory Address Temporary Data HintThis is also known as SR8085 Microprocessor MCQs for Interviews26). Data transfer in handshaking mode is called? Interrupt data-driven Synchronous Asynchronous DMA HintThe data transfer can be done synchronously.27). Universal shift register operates……modes? 1 2 3 4 HintIt operates in four modes Please refer to this link to know more about Shift Registers28). Which of the following instruction will affect the highest number of flags? DBR A RAL XRA A RBL HintIt is also called eXclusive OR accumulator29). Which of the following instructions is used with the Direction flag? Stack String Branch Arithmetic HintThese instructions work on strings of bytes30). The 8085 consists of…..outputs? 15 18 27 30 HintIt ranges from > 20 < 3031). Which of the following register is 16-bit in 8085? Register A Accumulator Register C Stack Pointer HintIt is a small register in the CPU of a computer32). 8085 microprocessor is designed by? Intel Dell IBM VAX HintIt is located in Santa Clara, California33). In 8085 microprocessor, the address bus with 16-bit can address up to? 8 KB 16 KB 32 KB 64 KB HintIt can address up to 64 kilobytes.34). How many general-purpose registers are there in 8085? 2 4 5 6 HintThey are B, C, D, E, H, and L35). The data within the stack is known as? Pulling data Pushed data Pushing data Pulled data HintThe data is transmitted into the stack36). The TRAP address in 8085 is? 002CH 0024H 0105H 013AH HintThis interrupt transmits the control toward the 0024H location37). The data transfer from…. to…. is not possible in a microprocessor? ACCU to memory Memory to ACCU ACCU to ACCU One memory to another memory HintThis microprocessor access upto 64Kb38). The term ‘EA’ in the microprocessor stands for? Enable address Efficient address Exclusive address Effective address HintThis is used in all kinds of microprocessors39). INTR stands for? Interrupt reset Interrupt response Interrupt request Interrupt ronaugh HintIt is a maskable interrupt in a microprocessor40). The example of a microprocessor-based on accumulator? Motorola 6809 Intel 8085 Intel 8086 Motorola 6807 HintIt is an 8-bit processor and launched in the year 197641). Which of the following signal not comes under the control bus? Reset Enable Read Write HintIt is also denoted with RST42). The technology used to design the first 8085 microprocessor is? TTL NMOS CMOS PMOS HintThis technology is very simple but slow43). The opcodes present in the 8085 microprocessor is…? 230 246 250 256 HintIt is an 8-bit microprocessor, so the possibility is 2^8 = 256 but includes only 24644). In 8085, the possibilities of mapping for memory registers are…? 54536 61536 65536 55536 HintThis processor includes 16-address lines so 2^16 memory registers can be simply mapped.45). The addressing mode used in the 8085 microprocessor for a list and array operations….? Immediate Indexed Direct Base register HintTo execute the instruction, it uses a stable value & index register.46). In 8085, the software interrupt is.? INTR RST-5 TRAP RST-5.5 HintThis is a vectored interrupt47). The hardware interrupt in 8085 is.? INTR RST-5 EA HLDA HintIt is one kind of maskable interrupt48). The address lines required to connect the microprocessor with a 4KB RAM is.? 10 12 20 25 HintIt ranges from above 10 and below 2049). BCD addition in 8085 can be performed by…instruction? DAA LXI LDA LHLD HintIt stands for decimal adjust after Addition50). The two-word instruction in 8085 microprocessor is…? IN 01H JMP 2085H MOV A, B ADC 2500H HintThe two-word instruction is IN 01H8085 Microprocessor MCQs for Exams51). Which of the following includes within ‘n’ instruction Memory Address of the data Instruction operates Operation code HintThe short form of this is known as opcode52). For which of the following flag, the conditional instructions are not dependent? AC C CY P HintIt is also called an auxiliary carry flag53). Which of the following chip is a DMA controller? 8237/57 8279 8253/54 8155 HintThe direct memory access controllers are 8237 or 825754). PSW of 8085 has five flags they are? S, Z, AC, P, OV S, OV, Z, AC, P S, Z, AC, P, CY S, Z, OV, P, CY HintFive flags of Processor status word in 8085 are S, Z, AC, P, CY55). In 8085 microprocessor, which of the below cycle is used to fetch & execute an instruction? Memory Instruction CLK Machine HintIt is also called a clock cycle56). BIU stands for? Bus interrupt unit Bus instruction unit Bus interface unit None HintIt works as an interface through the system bus57). What is the full form of IP? Instruction Pair Instruction Power Instruction Pointer Instruction Purpose HintOnce an instruction is fetched then instruction IP will be increased58). What is CS in a microprocessor? Component Set Code Segment Counter Segment Component Segment HintIt is also known as the text segment59). What is DS in a microprocessor? Declare Segment Data Segment Direct Segment Double Segment HintIt is an object file’s portion60). When the Accumulator is wide with 16-bit then it is called? AH AX DX AL HintIt is the primary type accumulator61). What is PROM? Programmable Read-Only Memory Post-Random Only Memory Pre Read-Only Memory Programmable Random Only Memory HintIt is one kind of digital memory62). What is EPROM? Electrical Programmable ROM Erasable Programmable ROM Enable Programmable ROM Erasable Programmable Random Only Memory HintIt stores the data even there is no power63). Which of the following is used to locate the data item to store? Fetch Database String Enable HintIt is a type of command used in SQL64). The computer ALU includes? Hard disks Registers Memory Counters HintThese are used by the CPU65). Which of the following ICs are used for processing the data? RAM ROM PROM Microcontrollers HintIt is also called programmable read-only memory66). An error within computer data is called? Halt Bug Mistake Inaccuracy HintWhen a fault occurs in a computer program67). The word length in a 32-bit microprocessor is equivalent to….? 3 byte 4 byte 5 byte 6 byte HintIt is equal to 0.004 kilobytes68). The access time of cache memory has….? Shortest Longest Middle None of the above HintThis memory is also called CPU memory69). In computers, which of the following part is used to calculate & compare? ALU Disk Control Modem HintIt is also known as arithmetic logic unit70). In a computer, the word length can be measured in…..? Bits Bytes Memory RAM HintIt is equal to 0.125 byte71). Which of the following processor was invented by Intel? 8009 4004 8090 8805 HintIt is a 4-bit CPU72). What is the SI stands for in a microprocessor? Source Index Source Interest Standard Index Segment Index HintIt is one kind of register in microprocessor73). What is BP stands for? Base Pointer Bus Pointer Byte Pointer Bit Pointer HintIt is used to access different parameters supplied by the stack74). The buses connected in the 8085A microprocessor are? 2 3 5 7 HintThe buses are address, control & data Please refer to this link to know more about Microprocessor75). Which of the following software is used to run a microprocessor? VHDL Assembly Language C Java HintIt is abbreviated like asm in some cases.8085 Microprocessor MCQs for Quiz76). Which of the following processor is programmed during the process of manufacturing? PROM EPROM MROM EEPROM HintIt is an alternative to the PROM77). In a machine, the o/p of the assembler is called as? Object program CNC program Symbolic addressing Source program HintThese programs are available in the form of machine language78). Which of the following pair of the register is used to specify memory? H & L E & D B & C X & Z HintThis pair acts as a memory pointer79). The nonmaskable interrupt examples in 8086…? intr trap rst5.5 rst6.7 HintIt is an asynchronous interrupt activated through an exception80). Which of the following load pointer is used to load the stack pointer? bhs bgt LDS RTS HintIt is a load pointer with DS81). In a flag register of 8085, how many FFs are there? 3 5 7 10 HintThe FFs are S, Z, AC, P, C82). Which flag is used in BCD operations of 8085? AC Z S P HintThis flag is known as auxiliary carry flag83). Which of the following addition is performed in DAA instruction of 8085? Binary BCD Octal Excess-3 HintIt is also called binary-coded decimal84). Which of the following instruction uses direct addressing? CMA STA RLC RRC HintIt stands for Store accumulator contents within memory85). Which of the following circuit is used to send out two messages simultaneously within a single direction? Simplex Duplex Diplex Quadruplex HintThat executes FDM or frequency-domain multiplexing86). Which of the following is not a control bus signal? READ RST or RESET ENABLE HOLD HintIt is one kind of signal87). Which of the following memory is used to retries the instructions? Virtual Main Cache Control HintThese are also called sometimes RAM & ROM88). The signal detached by the CPU to finish the operation of whole memory? Write Enable Read ALE HintThis is one kind of control signal89). The 8085 uses ….frequency? 2 MHz 3 MHz 10 MHz 15 MHz HintIt ranges from 3 to 690). The 4-index register in the microprocessor is used for? Division Multiplication Subtraction Arithmetic HintIt includes all the operations like addition, subtraction, division & multiplication91). What is IP in a microprocessor? Internet Protocol Instruction Pointer Internet Pointer Interrupt Protocol HintIt is also known as IAR or instruction address register92). Which of the following is a typical dedicated register? PC IP SP LR HintIt is one of the essential registers in the CPU93). What is the function of a logical unit within the computer’s CPU? To evaluate numbers To generate result To control information flow None of the above HintThis unit is used to compare two numbers94). What is the function of a logical unit within the computer’s CPU? To evaluate numbers To generate result To control information flow None of the above HintThis unit is used to compare two numbers95). Which of the following ICs are called the Si chips? RAM PROM ROM EPROM HintIt is also known as programmable read-only memory96). Which of the below ICs is not belongs to 8-bit? 8080 4004 8085 68000 HintIt is the first microprocessor launched by Intel97). The speed of any microprocessor can be determined in terms of…….? Based on Time Frequency of CLK Resistance Bits/Sec HintIt is measured in MHz98). The direction of the data line is? Bidirectional Unidirectional Tri-directional Multidirectional HintIt is also called as the data bus99). In which of the following RAM, Bipolar transistors are used? Static RAM Dynamic RAM DDR Permanent HintIt stores data in a stable form100). Dynamic RAM is designed by…..? MOS transistors ICs BJTs FETs HintThese are also known as MOSFETs Time is Up! Time's up
