Test1 Topics for Digital I – Spring 2009
Test will be closed book, closed notes, you will be given the Boolean Identities
1. Convert from decimal to binary and binary to decimal 2. Add, subtract and multiply with binary numbers 3. Use 2’s complement method to represent negative binary numbers
4. Given a Boolean function, create a truth table. 5. Given a truth table, write a Boolean function
6. Given a Boolean function, draw a logic circuit using the following gates:
7. Write down the Verilog primitives for the gates in #6 a-g 8. Explain the meaning of “x” and “z” in Verilog
9. Given the Boolean Identities, simplify a Boolean equation 10. Simplify a 2, 3 or 4 variable Boolean equation using a Karnaugh Map 11. Given a problem statement develop an appropriate output code 12. Given a combinational circuit write:
a. Structural Verilog code
b. Test strategy
c. Verilog testbench
13. Reproduce the following for half and full adder:
a. Governing logic equations
b. Logic circuits using gates
c. Logic circuits using hierarchy
14. Design a Ripple Carry Adder
15. Given a Verilog module, determine and write the function that the module
a. As a paragraph
b. As a logic circuit
c. As a Boolean equation
16. Basic combinational circuits that you should be able to use in a design:
a. Module declaration
b. I/O declarations
c. Internal variables declaration (e.g. wires)
d. Module instantiations
e. “Glue” logic
(C-problem) Make a truth table for this circuit:
(C-problem) Devise a minimal-length binary code to represent the state of a phone: on-hook, dial-tone, dialing, busy, connected, disconnected, ringing.
(B-problem) For your phone code write a Boolean equation that represents when the phone is off-hook (i.e., in a state other than on-hook or ringing).
(C-problem) Devise a one-hot code for the state of the phone.
(A-problem) Suppose a factory has two vats, only one of which is used at a time. The liquid in the vat in use needs to be at the right temperature, between 25?C and 30?C. Each vat has two temperature sensors indicating whether the temperature is above 25?C and above 30?C, respectively. The vats also have low-level sensors. The supervisor needs to be woken up by a buzzer when the temperature is too high or too low or the vat level is too low. He has a switch to select which vat is in use. Design a circuit of gates to activate the buzzer as required.