ECEN-454 Exam 1 questions and answers rated A+

ECEN-454 Exam 1 questions and
answers rated A+

Things that reduce Static Power - correct answer ✔✔ 1. Increase transistor length



2. Increase Vth



3. Decrease Vdd



4. Power Gating



5. Signal/State Encoding



Things that reduce Dynamic Power - correct answer ✔✔ 1. Shorter Interconnect



2. Increase Vth



3. Decrease Vdd



4. Clock Gating



5. Signal/State Encoding



Finding Arrival Time (STA) - correct answer ✔✔ 1. Start from beginning of each gate.

, 2. Take Max value for each node until you reach the output.



Finding Required Arrival Time (STA) - correct answer ✔✔ 1. Start from the output.



2. Take the min at each node until you get to the start of each gate.



Slack (STA) - correct answer ✔✔ Arrival Time - Required Arrival Time



Describe how to draw the schematic of a CMOS circuit. - correct answer ✔✔ PMOS on top.
NMOS on the bottom.

For NMOS:

A + B = A || B (parallel)

A*B = AB (series)



For PMOS:

A + B = AB (series)

A*B = A || B (parallel)

For PMOS, the gates all have bubbles.



Describe how to size transistors. - correct answer ✔✔ We want the resistance starting from VDD
or GND through any branch to be 1R at the output. That is, we want R/K to equal 1 at the
output.



What are the 4 types of delay? - correct answer ✔✔ (Worst Case)

Falling propagation delay

Rising propagation delay