Rules: Closed book and notes. Any type of calculator is allowed. Show all your work for full credit, using the standard methods. Please draw and write NEATLY (If I cannot read it, I must mark it WRONG). Do all work and put all answers on YOUR paper, not this sheet. Give a single answer, enclosed in a box if it's an equation or expression, to each question. Keep your work and the associated answer together, and carefully label them with the problem number and part number. Use only one side of the paper. Use the standard conventions and definitions that have been discussed in class.
1. [25 pts] Draw a proper bubble-to-bubble logic diagram of a 16-input priority encoder, using a minimal number of MSI and SSI packages. Create proper names for all external signals, which consist of 16 inputs to be encoded (where the highest bit number is the highest priority), a 4-bit encoded output, and a status bit output that indicates when one or more of the inputs are asserted. Label all components with their part numbers and standard pin names, but omit pin numbers.
2. [25 pts] Determine the maximum propagation delay from any input to any output of this 74LS circuit, using the worst-case analysis method. Describe the exact path used through the circuit and the individual delays, in addition to the total delay.
3. [25 pts] Draw a proper bubble-to-bubble logic diagram that will implement the following logic function using a standard decoder and a minimal number of SSI packages. Label all components with their part numbers and standard pin names, but omit pin numbers.
4. [25 pts] Draw the truth table and write an output equation for a 1-bit, 4-to-1 multiplexer. It has 4 data inputs (A0..A3), 2 enables (G1 and G2_L), 2 selects (S1 and S0), and 1 output (Y). The mux is enabled if either G1 or G2_L is asserted.
