This section contains more frequently asked Microprocessors 8085 Questions Bank with Answers in the various University Level and Competitive Examinations.
PRACTICE IT NOW TO SHARPEN YOUR CONCEPT AND KNOWLEDGE
1. If the crystal oscillator is operating at 15 MHz, the PCLK output of 8284 is
- 2.5 MHz.
- 5 MHz.
- 7.5 MHz.
- 10 MHz.
A. 2.5 MHz.
2. In which T-state does the CPU sends the address to memory or I/O and the ALE signal for demultiplexing
- T1.
- T2.
- T3.
- T4.
A. T1.
3. If a 1M ×1 DRAM requires 4 ms for a refresh and has 256 rows to be refreshed, no more than __________ of time must pass before another row is refreshed.
- 64 ms.
- 4 ns.
- 0.5 ns.
- 15.625 µs .
B. 4 ns.
4. In a DMA write operation the data is transferred
- from I/O to memory.
- from memory to I/O.
- from memory to memory.
- from I/O to I/O.
A. from I/O to memory.
5. Which type of JMP instruction assembles if the distance is 0020 h bytes
- near.
- far
- short
- none of the above.
A. near.
6. A certain SRAM has CS = 0 , WE = 0 and OE = 1. In which of the following modes this SRAM is operating
- Read
- Write
- Stand by
- None of the above
B. Write
7. Which of the following is true with respect to EEPROM?
- contents can be erased byte wise only.
- contents of full memory can be erased together
- contents can be erased using ultra violet rays
- contents can not be erased
C. contents can be erased using ultra violet rays
8. Pseudo instructions are basically
- false instructions.
- instructions that are ignored by the microprocessor
- assembler directives
- instructions that are treated like comments
C. assembler directives
9. Number of the times the instruction sequence below will loop before coming out of loop is MOV AL, 00h A1: INC AL JNZ A1
- 0
- 1
- 255
- 256
D. 256
10. What will be the contents of register AL after the following has been executed MOV BL, 8C MOV AL, 7E ADD AL, BL
- 0A and carry flag is set
- 0A and carry flag is reset
- 6A and carry flag is set
- 6A and carry flag is reset
A. 0A and carry flag is set
