Company: Cisco Systems

CISCO Placement Paper

Technical (Digital)

Nasik, 2009

1. Add the following BCD numbers— 1001 and 0100

2. How much time does a serial link of 64 Kbps take to transmit a picture with 540 pixels.

3. Give the output when the input of a D-flip flop is tied to the output through the XOR gate.

4. Simplify the expression AB + A( B + C ) + B ( B + C )

5. Determine the logic gate to implement the foolowing terms–ABC, A+B+C
6. Implement the NOR gate as an inverter.

7. What is the effect of temperature on the Icb in a transistor

8. What is the bit storage capacity of a ROM with a 512*4 organisation?

9. What is the reason of the refresh operation in dynamic RAM’s ?

10. Suppose that the D input of a flip flop changes from low to high in the middle of a clock pulse.Describe what happens if the flip flop is a positive edge triggered type?

11. How many flip flops are required to produce a divide by 32 device ?

12. An active HIGH input S-R latch has a 1 on the S input and a 0 on the R input. What state is the latch in?

13. Implement the logic equation Y = C^BA^ + CB^A + CBA with a multiplexer. (where C^ stands for C complement)

14.Equivalent Gray code reprasentation of AC2H.

15. What does a PLL consist of ?

We advice you to know the design of PLL as questions pertaining to this may be asked