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 : 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 is wrong a) INC DPTR b) MOV @DPTR, A c) MOV A, @A+DPTR d) DEC DPTR
Last Answer : d) DEC DPTR
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 : What instruction performs Compare immediate to indirect and jump if not equal. a) CJNE A, #data, rel b) CJNE Rn, #data, rel c) CJNE @ Ri, #data, rel d) CJNE A, data, rel
Last Answer : b) CJNE Rn, #data, rel
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 : Which of the following instruction is used to set bit port directly? a) SET P1.0 b) MOV P1.0, bit c) SETB P1.0 d) JB P1.0, bit
Last Answer : JB P1.0, bit
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 : 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
Description : What is the Result of RR A instruction if accumulator contains 1000 0000. a) 0000 0001 b) 0000 0000 c) 0100 0000 d) 0000 0010
Last Answer : a) 0000 0001
Description : A storage area used to store data to a compensate for the difference in speed at which the different units can handle data is a. Memory b. Buffer c. Accumulator d. Address
Last Answer : b. Buffer
Description : A group of bits that tell the computer to perform a specific operation is known as_______ A. Instruction code B. Micro-operation C. Accumulator D. Register
Last Answer : A. Instruction code
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 : 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 interrupt is generated, if ____ bits are set a) IE b) RI, IE c) IP, TI d) RI, TI
Last Answer : a) IE
Description : Interrupts which are initiated by an instruction are a. internal b. external c. hardware d. software
Last Answer : b. external
Last Answer : d. software
Description : The ___________ contains the address of the next instruction to be executed. a) IR b) PC c) Accumulator d) System counter
Last Answer : Answer: b Explanation: PC stands for program counter (It contains the address of the next instruction to be executed)
Description : The load instruction is mostly used to designate a transfer from memory to a processor register known as_________ A. Accumulator B. Instruction Register C. Program counter D. Memory address Register
Last Answer : A. Accumulator
Description : A basic instruction that can be interpreted by computer generally has ________ A. An operand and an address B. decoder and an accumulator C. Sequence register and decoder D. None of the Above
Last Answer : A. An operand and an address
Description : The content of the accumulator after the execution of the following 8085 assembly language program, is MVI A, 35H MOV B, A STC CMC RAR XRA B (A) 00H (B) 35H (C) EFH (D) 2FH
Last Answer : (D) 2FH
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 : 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 : The subprogram finish the return instruction recovers the return address from the: a. Queue b. Stack c. Program counter d. Pointer
Last Answer : b. Stack
Description : Single address computer instruction has two parts: a. The operation code b. The operand c. A and B d. None of these
Last Answer : c. A and B
Description : How many parts of single address computer instruction : a. 1 b. 2 c. 3 d. 4
Last Answer : b. 2
Description : Memory access in RISC architecture is limited to instructions a. CALL and RET b. PUSH and POP c. STA and LDA d. MOV and JMP
Last Answer : c. STA and LDA
Description : which chips using special external equipment can reprogram a. ROM b. PROM c. SAM d. RAM
Last Answer : b. PROM
Description : Various machine level components are: a. Address register > Program counter c Data register d. Accumulator register e. Memory of 2K,16 bits/word RAM f. Multiplexers g. Allof these
Last Answer : g. Allof these
Description : A memory that is capable of determining whether a given datum is contained in one of its address is a. ROM b. PROM c. CAM d. RAM
Last Answer : c. CAM
Description : If in a computer, 16 bits are used to specify address in a RAM, the number of addresses will be a. 216 b. 65,536 c. 64K d. Any of the above
Last Answer : b. 65,536
Description : In linear decoding address bus of 16-bit wide can connect only ____ of RAM. a. 16 KB b. 6KB c. 12KB d. 64KB
Last Answer : b. 6KB
Description : What are the functions of an accumulator?
Last Answer : The accumulator is the register associated with the ALU operations and sometimes I/O operations. It is an integral part of ALU. It holds one of data to be processed by ALU. It also temporarily stores the result of the operation performed by the ALU.
Description : Actual data processing operations are performed in the arithmetic logic section, but not in the …. Storage section of a processor unit a. Primary b. Accumulator c. Buffer d. Secondary
Last Answer : a. Primary
Description : Which is used to store critical pieces of data during subroutines and interrupts: a. Stack b. Queue c. Accumulator d. Data register
Last Answer : a. Stack
Description : LA stands for: a. Load accumulator b. Least accumulator c. Last accumulator d. None of these
Last Answer : a. Load accumulator
Description : Accumulator based microprocessor example are: a. Intel 8085 b. Motorola 6809 c. A and B d. None of these
Description : In Microprocessor one of the operands holds a special register called: a. Calculator b. Dedicated c. Accumulator d. None of these
Last Answer : c. Accumulator
Description : Which bus transfer singles from the CPU to external device and others that carry singles from external device to the CPU: a. Control bus b. Data bus c. Address bus d. None of these
Last Answer : a. Control bus
Description : In 8051 an external interrupt 1 vector address is of ________ and causes of interrupt if ____. a) 000BH, a high to low transition on pin INT1 b) 001BH, a low to high transition on pin INT1 c) 0013H, a high to low transition on pin INT1 d) 0023H, a low to high transition on pin INT1
Last Answer : a) 000BH, a high to low transition on pin INT1
Description : 8096 write-protected mode, no code can write to memory address between __. a) 2020 to 3FFFH b) 8000 to FFFFH c) 2000 to 3FFFH d) 2020 to 202FH 17. If the __ pin is ___ , then we have the option ... b) EA, low, internal, external c) EA, high, external, internal d) EA, low, external, internal
Last Answer : c) EA, high, external, internal
Description : What the Difference between accumulator and instruction register 8080?
Last Answer : Examples: /360: no accumulator 8080: A 6800: A and B 8086: AX ...
Description : In microprocessor the next instruction to be executed is stored in a) Program Counter b) Stack Pointer c) Memory Pointer d) Accumulator
Last Answer : Ans: Program Counter
Description : The act of writing new data into register (1) is possible only when the register is an accumulator (2) is possible only when the register is an accumulator or instruction register (3) erases the previous contents of the register (4) is non-destructive to existing contents
Last Answer : is possible only when the register is an accumulator or instruction register