Computer Science Department
College of Arts and Sciences
Solve exercises 1.5, 1.8, 1.11, 1.15, 1.20 from the textbook (Mano, "Computer System Architecture", 3rd Edition).
A led display is composed of 7 "bars" that could be turned ON or OFF individually and independently. The bars are numbered as shown below:
1 ----- | | 4 | | 5 | 2 | |-----| | | 6 | | 7 | 3 | -----By turning ON or OFF a particular set of bars, different digits could be displayed. For example, to display the number "2", bars # 1, 5, 2, 6, and 3 must be turned ON while all others are turned off. The led circuit has 7 wires W1, W2, W3, W4, W5, W6, W7, each corresponding to a particular bar. By setting a wire to a value of "1" (e.g. 5 volts), its corresponding bar lights up. By setting a wire to a value of "0" (e.g. 0 volts or ground), its corresponding bar turns off.
We are given a decimal number (between 0 and 9) in 4 bits A3, A2, A1, A0, where A3 is the most significant bit and A0 is the least significant bit and we are asked to design a logic circuit that drives the LED display described above in such a way that the LED display shows the value of the 4 bits A3, A2, A1, A0. Since we are only interested in digital numbers, the LED display is "free" to display whatever it wants if the value of A3, A2, A1, A0 is greater than 9.
Find a minimal logic circuit that implements this task. For each wire of the LED display, show the simplification map and write down the minimal boolean expression for that wire.
The following input-output behavior was exhibited by a finite state machine. What is the least number of states in this machine? Find an appropriate state table. Is that table unique?
Input: 0 0 0 0 1 0 0 0 1 0 0 0 1 0 Output: 0 1 0 1 0 0 0 0 1 0 1 0 0 1Repeat for the following sequence.
Input: 1 1 1 0 1 1 1 0 1 0 1 0 1 0 0 0 0 1 0 0 0 1 1 0 Output: 0 1 0 1 1 0 1 1 0 1 1 1 0 1 1 1 1 1 1 1 1 0 1 1
Maintainer: Azer Bestavros Created on: 1996.09.03 Updated on: 1996.09.03