Homework 5.

Asynchronous Pulse Mode

Analysis (Problem 1 and 2):Problem 1.A. Determine state tableB. Construct a timing diagram that shows the overall response of the circuit. Include

x1,x2,x3,y1,y2,Y1,Y2, and z in the timing diagram.

Problem 2.A. Determine state tableB. Determine the output response to the input sequence x1-x2-x1-x1-x1-x1-x2-x2 if starting

from state 00C. What form (level or pulse) will an output of z = 1 have? Why?

Problem 3. Design a two input (x1, x2) and a output where an output transition 0 to 1 occurs onthe occurrence of the last x2 pulse in the sequence of x1-x2-x1-x2. The output goes back to 0only after the first x1 pulse following a 0 to 1 transition. No overlapping sequences. Designusing SR Latch.

State\x1x2 00 01 11 10

1 1/0 2/- -/- 3/-

2 4/- 2/1 5/- -/-

3 1/- -/- 5/- 3/0

4 4/- 2/- -/- 6/-

5 -/- 2/- 5/- 6/-

6 1/- -/- 5/- 6/1

Asynchronous Fundamental Mode

Problem 1. AnalysisA. Determine the excitation table and outputB. Construct flow tableC. Use the flow table to determine the output response to the input sequence x1x2: 00-01-11-10-

00-01-00-10. Assume initially x1=x2=y1=y2=Y1=Y2=0

Problem 2. Primitive flow table designA fundamental mode circuit must be designed to satisfy the following requirements. Two inputs(x1, x2) and one output (z) are required. The output z=0 will always be produced when x1=x2.When x1=0 and x2 changes from 0 to 1, an output z=1 must occurs. When x1=1 and x2 changesfrom 1 to 0, an output z=1 must occurs. Otherwise, no input change will cause an output change.Determine the primitive flow table.

Problem 3. Flow table reductionReduce the following flow table.

Problem 4. Complete Asynchronous Circuit DesignA Fundamental mode circuit is to be designed to function as an electronic lock. The lock has twoswitch inputs (x1 and x2). Design the circuit such that an open signal (z=1) is produced onlyafter the following conditions have been satisfied.A. Begin with x1=x2=0

B. While x2=0, x1 turned on, then off twice.C. While x1 remains off, x2 is turned on to open the lock