Final Review Flashcards
An input table with n inputs should have how many binary entries?
2^n
Two transistors connected in series form what logic operation?
AND
Two transistors in parallel implement what logic operator?
OR
What is the difference between analysis and synthesis?
Analysis is done on existing networks, synthesis is creating new networks
Functional verification is what?
The process of applying all input combinations to a network and measuring the outputs in a truth table
What is the definition of functionally equivalent?
Two networks of different construction that implement the same overall function
Perfect Induction is what process?
Constructing truth tables for a boolean function that is to be analyzed, and checking all of the outputs manually
An expression containing two or more AND terms ORed together is what kind of expression?
Sum of products, Product of sums is the reverse (ORs ANDed)
Each unique SOP product term is called what?
Minterm
Maxterms correspond to cells in the K-Map or Rows in the truth table where the output is what?
0
Which two gate types have universality?
NAND and NOR
What causes errors during transmission?
Electrical Noise
What is a parity bit and how are they generated?
An additional bit appended to the package; 0 for an even number of 1s, 1 for odd.
Functions with don’t care conditions have what title?
Incompletely Specified
In what case would the carry bit of an addition be ignored?
If the numbers were represented in 2s compliment
A full adder can be constructed with how many half adders?
Two
An n bit adder adds numbers of what bit length?
n
What is a circuit’s critical path?
The longest gate delay possible.
Why would ripple adders be used instead of lookahead adders?
Ripple adders are cheaper
What is a noise margin?
The maximum noise voltage added to the input of a digital circuit
What does CMOS stand for?
Complementary Metal-Oxide-Semiconductor
What is the difference between NMOS and PMOS transistors
NMOS is open at a gate voltage 0, PMOS is closed
What type of transistor is denoted with a circle on the gate input?
PMOS
What transistors are used for the upper and lower networks, and what are their functions?
Upper: PMOS, Load
Lower: NMOS, Logic
What parameter of a transistor is varied to decease propagation delay
Width
What is the fan-in of a logic gate
The number of gate inputs
What is the fan-out of a gate?
The amount of gates that it drives, also called load
Drivers are constructed using what logic gates and for what purpose?
Two CMOS inverters with high W in order to increase current flow
Shannon’s expansion theorem does what?
Expands a boolean function in terms of one variable
Sequential logic circuits depend on what?
Both current state and past state inputs
A D latch ties the data input to what
The set and reset
Under what condition does a JK FF behave like a T FF
J=K=1
What is the difference between a Moore and a Mealy machine
Moore depends only on states, Mealy depends on states and primary inputs
When states are assigned to binary sequences where only one bit is one that is the process of what?
one-hot encoding
Which type of state machine reacts quicker?
Mealy Machines
What are the main parts of a digital system?
Datapath Circuit, Control Circuit, Memory, Bus, I/O ports
What two numbers are associated with a memory cell?
Content (stored data) and Capacity/Density (size of the memory)
What is the difference between RAM and ROM
Random access memory both reads and writes, read only memory contains permanent binary information
What is volatile memory?
Memory that only works as long as it’s powered
What is the difference between SRAM and RAM
SRAM will keep data permanently without needing to be refreshed, but needs to be powered.
What is the difference between ASIC using standard cells and gate arrays?
Standard cells store operations in a library, not on chip, and are connected during fabrication. Gate arrays are connected after fabrication.
PLA and PAL differ how?
PLA has a programmable AND plane, PAL has a programmable AND and OR plane
