Description : Which of the following instruction is of logical instructions? i) CPL A ii) JC rel iii) DA A iv) ANL A, Rn v) RR A vi) CPL bit a) i, v b) v, iii, I c) iv, ii d) v, iii, ii
Last Answer : c) iv, i
Description : Which of the following instruction perform the move accumulator to external RAM of 16bit address? a) MOV @ DPTR, A b) MOVX @ Ri, A c) MOV A, @ Ri d) MOVX @ DPTR, A
Last Answer : c) MOV A, @ Ri
Description : Which of the following instruction perform as of indirect RAM to accumulator? a) MOV A, Rn b) MOV @Ri, A c) MOV A, @Ri d) MOV Rn, A
Last Answer : c) MOV A, @Ri
Description : Which of the following instruction perform jump indirect relative to DPTR a) JMP A+DPTR b) JMP DPTR c) JMP @A+DPTR d) SJMP A+DPTR
Last Answer : b) JMP DPTR
Description : The conditional branch instruction JNS performs the operations when if __ a) ZF =0 b) SF=0 c) PF=0 d) CF=0
Last Answer : b) SF=0
Description : The most common addressing techiniques employed by a CPU is a. immediate b. direct c. indirect d. register e. all of the above
Last Answer : e. all of the above
Description : Explain the following instructions. SWAP A ADD C MUL AB CJNE A, add, radd MOV A, R0 MOVX A, @ A + DPTR.
Last Answer : SWAP A Description: This instruction exchanges bits 0-3 of the Accumulator with bits 4-7 of the Accumulator. This instruction is identical to executing "RR A" or "RL A four times ... referred to as the base address and the accumulator value is referred to as the index address.
Description : In immediate addressing the operand is placed a. in the CPU register b. after OP code in the instruction c. in memory d. in stack
Last Answer : b. after OP code in the instruction
Description : Serial port interrupt is generated, if ____ bits are seta) IE b) RI, IE c) IP, TI d) RI, TI
Last Answer : d) RI, TI
Description : Serial port vector address is of _______. And causes an interrupt when ________. a) 0013H, either TI or RI flag is set b) 0023H, either TI or RI flag is reset c) 0013H, either TI or RI flag is reset d) 0023H, either TI or RI flag is set
Last Answer : a) 0013H, either TI or RI flag is set
Description : Serial port interrupt is generated, if ____ bits are set a) IE b) RI, IE c) IP, TI d) RI, TI
Last Answer : a) IE
Description : System calls are usually invoked by using: (A) A privileged instruction (B) An indirect jump (C) A software interrupt (D) Polling
Last Answer : (C) A software interrupt
Description : In which addressing mode the operand is given explicitly in the instruction? A. Absolute B. Immediate C. Indirect D. Direct
Last Answer : B. Immediate
Description : RISC stands for: a. Reduced Instruction set computer b. Reduced Instruct set compare c. Reduced instruction stands computer d. All of these 107. DEC stands for:
Last Answer : a. Reduced Instruction set computer
Description : Which of the following is of compare instruction in 8087? a) FTST b) FPREM c) FPATAN d) FLDI
Last Answer : a) FTST
Description : How does the microprocessor differentiate between data and instruction
Last Answer : When the first m/c code of an instruction is fetched and decoded in the instruction register, the microprocessor recognizes the number of bytes required to fetch the entire ... will be considered as data & the byte after the data will be treated as the next instruction.
Description : When the RET instruction at the end of subroutine is executed, a. the information where the stack is iniatialized is transferred to the stack pointer b. the memory address of the RET instruction is ... two data bytes stored in the top two locations of the stack are transferred to the stack pointer
Last Answer : c. two data bytes stored in the top two locations of the stack are transferred to the program counter
Description : What is the control unit's function in the CPU? a. To transfer data to primary storage b. to store program instruction c. to perform logic operations d. to decode program instruction
Last Answer : b. to store program instruction
Description : Which of the following registers is used to keep track of address of the memory location where the next instruction is located? a. Memory Address Register b. Memory Data Register c. Instruction Register d. Program Register
Last Answer : d. Program Register
Description : Which of the following registers is used to keep track of address of the memory location where the next instruction is located? a. Memory address register b. Memory data register c. Instruction register d. Program counter
Last Answer : d. Program counter
Description : Which of the following registers is loaded with the contents of the memory location pointed by the PC? a. Memory address register b. Memory data register c. Instruction registers d. Program counter
Last Answer : c. Instruction registers
Description : Which of the following registers is loaded with the contents of the memory location pointed by the PC? a. Memory address registers b. Memory data registers c. Instruction register d. Program counter
Last Answer : c. Instruction register
Description : In 8085, which of the following performs: load register pair immediate operation? (1) LDAX rp (2) LHLD addr (3) LXI rp, data (4) INX rp
Last Answer : Answer: 3
Description : The two basic types of record-access methods are a. Sequential and random b. Sequential and indexed c. Direct and immediate d. On-line and real time
Last Answer : a. Sequential and random
Description : Where does a computer add and compare data? a. Hard disk b. Floppy disk c. CPU chip d. Memory chip
Last Answer : c. CPU chip
Description : Outputs of instruction/data path in CU are. a. Reg R/W b. Load/Reg-Reg c. ALU function select d. Load control e. Read control f. IR Latch g. JUMP/Branch/Next PC h_ = All of these
Last Answer : h_ = All of these
Description : Why do we use XRA A instruction
Last Answer : The XRA A instruction is used to clear the contents of the Accumulator and store the value 00H.
Description : Explain the different instruction formats with examples
Last Answer : The instruction set is grouped into the following formats • One byte instruction MOV C,A • Two byte instruction MVI A,39H • Three byte instruction JMP 2345H
Description : Mention the categories of instruction and give two examples for each category
Last Answer : The instructions of 8085 can be categorized into the following five • Data transfer MOV Rd,Rs STA 16-bit • Arithmetic ADD R DCR M • Logical XRI 8-bit RAR • Branching JNZ CALL 16-bit • Machine control HLT NOP
Description : What is an instruction?
Last Answer : An instruction is a binary pattern entered through an input device to command the microprocessor to perform that specific function
Description : Define instruction cycle, machine cycle and T-state
Last Answer : Instruction cycle is defined, as the time required completing theexecution of an instruction. Machine cycle is defined as the time required completing one operation of accessing memory, I/O or ... request. Tcycle is defined as one subdivision of the operation performed in one clock period
Description : Explain the difference between a JMP instruction and CALL instruction.
Last Answer : A JMP instruction permanently changes the program counter. A CALL instruction leaves information on the stack so that the original program execution sequence can be resumed.
Description : How many operations are there in the instruction set of 8085 microprocessor?
Last Answer : There are 74 operations in the 8085 microprocessor.
Description : CISC stands for: a. Complex instruction set computer b. Camper instruct set of computer c. Compared instruction set computer d. None of these
Last Answer : a. Complex instruction set computer
Description : ISA stands for: a. Instruct set area b. Instruction set architecture c. Both a and b d. None of these
Last Answer : b. Instruction set architecture
Description : Which is not the main feature of DEC Alpha: a. 64 Bit RISC processor b. Designed to replace 32 VAX(CISC) c. Seven stage split integer/floating point pipeline d. Variable Instruction length
Last Answer : d. Variable Instruction length
Description : How many speed of 8088,8085,8086 microprocessor: a. 2.5 Million instruction per second b. 1.5 Million instruction per second c. 3.5 Million instruction per second d. 1.6 Million instruction per second
Last Answer : a. 2.5 Million instruction per second
Description : Which is most commonly measured in terms of MIPS previously million instruction per second: a. Microprocessor b. Performance of a microprocessor c. Assembly line d. None of thes
Last Answer : b. Performance of a microprocessor
Description : RISC stands for: a. Reduced Instruction Set Computer b. Reduced Intergraded Set Computer c. Resource Instruction Set Computer d. Resource Instruction System Computer
Last Answer : a. Reduced Instruction Set Computer
Description : CISC stands for: a. Complex Instruction System Computer b. Complex Instruction Set Car c. Complex Instruction Set Computer d. None of these
Last Answer : c. Complex Instruction Set Computer
Description : Interrupts which are initiated by an instruction are a. internal b. external c. hardware d. software
Last Answer : b. external
Description : When a subroutine is called, the address of the instruction following the CALL instructions stored in/on the a. stack pointer b. accumulator c. program counter d. stack
Last Answer : d. stack
Description : Pipeline implement a. fetch instruction b. decode instruction c. fetch operand d. calculate operand e. execute instruction f. all of abve
Last Answer : f. all of abve
Last Answer : d. software
Description : Pipelining strategy is called implement a. instruction execution b. instruction prefetch c. instruction decoding d. instruction manipulation
Last Answer : b. instruction prefetch
Description : 8253, 8257 c) 8257,8251 d)8251,825721.Consider the following set of 8085 instruction.MVI A,82HORA AJP DSPLYXRA ADSPLY:OUT PORT1HLT.The output at PORT1 isa) 00H b) FFH c) 92H d) 11H
Last Answer : a) 00H
Description : The contents of accumulator before CMA instruction is A5H. Its content after instructionexecution isa) A5H b) 5AH
Last Answer : b) 5AH
Description : In an 8085 microprocessor, the instruction CMP B has been executed while the contentsof accumulator is less than that of register B. As a result carry flag and zero flag will berespectively (A) set, reset (B) reset, set (C) reset, reset (D) set, set
Last Answer : (A) set, reset