8085 Interview Questions and Answers

8085 Interview Questions and Answers
1)What are level-triggering interrupt?
Ans:RST 6.5 & RST 5.5 are level-triggering interrupts
2)What does Quality factor mean?
The Quality factor is also defined, as Q. So it is a number, which
reflects the lossness of a circuit. Higher the Q, the lower are the
3)Which interrupt is not level-sensitive in 8085?
RST 7.5 is a raising edge-triggering interrupt.
4)Why crystal is a preferred clock source?
Because of high stability, large Q (Quality Factor) & the frequency

that doesn't drift with aging. Crystal is used as a clock source most
of the times.
5)Can an RC circuit be used as clock source for 8085?
Ans:Yes, it can be used, if an accurate clock frequency is not required.

Also, the component cost is low compared to LC or Crystal.
6)What are input & output devices?
Keyboards, Floppy disk are the examples of input devices. Printer, LED

/ LCD display, CRT Monitor are the examples of output devices.
7)In 8085 which is called as High order / Low order Register?
Flag is called as Low order register & Accumulator is called as High

order Register.
8)What is the RST for the TRAP?
RST 4.5 is called as TRAP.
9)What is clock frequency for 8085?
3 MHz is the maximum clock frequency for 8085.
10)How many interrupts are there in 8085?
There are 12 interrupts in 8085.
11)Name 5 different addressing modes?
1. Immediate

2. Direct
3. Register
4. Register indirect
5. Implied addressing modes.
12)Which interrupt has the highest priority?
TRAP has the highest priority.
13)What are Software interrupts?
14)What are Hardware interrupts?
TRAP, RST7.5, RST6.5, RST5.5, INTR
15)In what way interrupts are classified in 8085?
In 8085 the interrupts are classified as Hardware and Software interrupts.

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