Which of the following instructions of an 8086 microprocessor uses the contents of a CX register as a counter?
A. Only 1 and 2
B. Only 1 and 3
C. Only 2 and 3
D. 1, 2 and 3
Select an option to see the answer and solution.
What is the capacity of internal RAM in 8051 microcontroller?
A. 128 bytes
B. 256 bytes
C. 4 KB
D. 8 KB
Select an option to see the answer and solution.
Which of the following is not a characteristic of transparent DMA mode of I/O operation?
A. The external logic steals cycles from the CPU
B. The normal rate of execution is slowed down
C. Only one word can be transferred at a time
D. Data is transferred to/from memory directly
Select an option to see the answer and solution.
Which of the following peripherals provide I/O facilities?
Select an option to see the answer and solution.
Determine the contents of register AL in 8086 after the following instructions have executed
A. O2H-carry flag set
B. OAH-carry flag set
C. O1H- carry flag not set
D. OFH - carry flag set
Select an option to see the answer and solution.
The interface chip used for data transmission between 8086 and a 16 bit ADC is
Select an option to see the answer and solution.
As compared to 16 bit microprocessor, 8 bit microprocessors are limited in
A. 1 and 2 only
B. 2 and 3 only
C. 1 and 3 only
D. 1, 2 and 3
Select an option to see the answer and solution.
Which of following is used to reset entire interrupt structure in 8051 microcontroller?
Select an option to see the answer and solution.
In 8051, Match the following
Branch Instruction Addressing Jumping distance
a. LJMP
1. Relative
W. 11 bits
b. AJMP
2. Indirect
X. 16 bits
c. SJMP
3. Direct
Y. 8 bits
d. JMP@A+DPTR
4. Direct
Z. 16 bits
A. a 3 X, b 4 W, c 1 Y, d 2 Z
B. a 2 W, b 3 X, c 4 Y, d 1 Z
C. a 4 Z, b 3 Y, c 2 X, d 1 W
D. a 1 W, b 2 X, c 3 Y, d 4 Z
Select an option to see the answer and solution.
In 8085, if the clock frequency is 5 MHz, the time required to execute an instruction of 18 T states is
A. 3.0 µs
B. 3.6 µs
C. 4.0 µs
D. 6.0 µs
Select an option to see the answer and solution.
What is the Power supply specification for 8085 microprocessor?
A. Single +5V supply with 10% voltage margins
B. Dual +5V supply with 10% voltage margins
C. Single +10V supply with 5% voltage margins
D. Dual +5V supply with 5% voltage margins
Select an option to see the answer and solution.
Which one of the following registers of 8085 microprocessor is not a part of programming model?
A. Instruction register
B. Memory address register
C. Status register
D. Temporary data register
Select an option to see the answer and solution.
In the 8085 microprocessor, the RST 6 instruction transfers the program execution to the following location:
Select an option to see the answer and solution.
In 8051, description of ANL A, direct is
A. AND register to accumulator
B. AND byte into indirect address to accumulator
C. AND immediate data to accumulator
D. AND byte into direct address to accumulator
Select an option to see the answer and solution.
An interrupt in which an external device supplies its address and the interrupt request, is called:
A. Poll interrupt
B. Maskable interrupt
C. Non-maskable interrupt
D. Vectored interrupt
Select an option to see the answer and solution.
In the 8086 instruction ADD DX, [BX][CI], the addressing mode of source operand is
A. Register
B. Register indirect
C. Based indexed
D. Direct
Select an option to see the answer and solution.
Which of the following is not true for a counter instruction in PLC?
A. Up-counters are always reset to zero
B. The counter will operate on the trailing edge
C. A separate coil is used for reset
D. All of these
Select an option to see the answer and solution.
In 8051, the accumulator register contains 80H and B register contains 8FH. The content of the accumulator and status of the carry flag after the addition operation are respectively,
A. 0FH, 1
B. 10FH, 0
C. FFH, 1
D. 10FH, 1
Select an option to see the answer and solution.
Calculate the size of memory address space for a 16 bit data and 20 bit address bus.
Select an option to see the answer and solution.
The 8086 arithmetic instructions work on
A. 1 and 2
B. 2 and 3
C. 1 and 3
D. 1, 2, and 3
Select an option to see the answer and solution.
