ECS154A Homework #3

• Written homework due by 12:10PM on Monday, July 16th.
• Logisim assignments due by 11:59PM on Sunday, July 15th. Submit your assignment via Smartsite.
  

Assignment (Due by 11:59PM on Sunday, July 22nd)

• See CPU.html

Assignment (Written):

1. Do Problem 8.2 in the book
2. Do Problem 8.5 in the book, detecting 110 or 111 patterns
3. Do Problem 8.6 in the book, detecting 110 or 111 patterns

Assignment (Logisim):

1. Do Problem 8.11 in the book (detecting 1001 or 0111 patterns) and implement.
2. Do Problem 8.12 in the book, only do it over 4 bits and make p=1 if the number of 1's is even. Implement the circuit.

3. Consider a coin-operated vending machine. Assume that the
   machine accepts only quarters, dimes, and nickels. Coins are inserted 
   until a total of 30 cents or more is deposited. Only 
   one coin is deposited at a time. The output signal z1=1 should indicate 
   that merchandise should be provided; z1=0 indicates no merchandise.
   
   Coincident with the last coin input, the (change) outputs are to be set.
   Assume the machine can give a dime (z2=1) and/or a nickel (z3=1).
   Use the binary outputs z2 and z3 to represent the 4 distinct possibilities
   (No change, 1 nickel, 1 dime, 1 nickel and 1 dime.)  If a customer does
   something unwise, like puts in a dime and a nickel followed by a quarter, 
   correct change does not have to be provided (but the maximum amount change 
   does.)
   
   Design the circuit in Logisim.