Download Spring 1999 EECS 145M Microcomputer Interfacing Lab Final Exam and more Exams Microcomputers in PDF only on Docsity!
NAME (please print)
STUDENT (SID) NUMBER
UNIVERSITY OF CALIFORNIA
College of Engineering Electrical Engineering and Computer Sciences Berkeley
EECS 145M: Microcomputer Interfacing Lab
LAB REPORTS:
1 _________________ 2 __________________ 3 ___________________
8 _________________ 9 __________________ 10 ___________________
21 _________________ 22 __________________ 23 ___________________
24 _________________
Total of top 4 Lab Grades Total of top 4 Question Sections Lab Bonus Lab Participation Mid-Term # Mid-Term # Final Exam Total Course Grade
_______________ (400 max) _______________ (100 max)
_______________ (100 max) _______________ (100 max) _______________ (100 max) _______________ (200 max) _______________ (1000 max)
COURSE LETTER
GRADE
Spring 1999 FINAL EXAM (May 21)
Answer the questions on the following pages completely, but as concisely as possible. The exam is to be taken closed book. Use the reverse side of the exam sheets if you need more space. Calculators are OK. In answering the problems, you are not limited to the particular equipment you used in the laboratory exercises.
Partial credit can only be given if you show your work.
FINAL EXAM GRADE :
1 __________ (36 max) 2 __________ (60 max) 3 _________ (104 max)
TOTAL __________ (200 max)
PROBLEM 1 (total 36 points):
Define the following terms:
1a. (6 points) Transition voltages of an analog-to-digital converter
1b. (6 points) Nyquist sampling theorem
1 c. (6 points) Tri-state buffer
PROBLEM 2 (total 60 points):
You have been chosen to design a microcomputer system for timing the swimming events in the Summer Olympic Games.
- There are 12 swimmers and the pool has 12 lanes. Each swimmer starts at the one end of the pool and, at the sound of a gunshot, jumps in and swims to the opposite end of the pool in their own lane
- When they reach the opposite end of the pool, the swimmers make contact with a switch (called a “touch plate”) mounted on the wall of the pool. When the switch is touched, the contacts stay closed until manually reset.
- The athletic event is started by the starter’s pistol, which closes an electrical contact when the trigger is pulled
- Your computer system detects the contact closure and immediately sends a pre-recorded gunshot sound to 12 speakers, each located behind a swimmer. (this gives each swimmer a fair start and also avoids using chemical explosives).
- There is an external timing circuit mounted near each touch plate. Each has a 24-bit counter that is set to zero by a “Start” input pulse, increases by one every 100 μs, and is stopped by a “stop” input pulse. The start and stop input lines float high when disconnected and can be brought low by connecting to ground.
10 kHz counter
24
Start Stop
- Your microcomputer has three 16-bit input ports, two 16-bit output ports, and NO analog I/O. The input port lines float high when disconnected and can be brought low by connecting to ground.
- The gunshot sound is in a digital file and you have a software function that sends the digital data to one of the output ports at the correct speed.
- You have an external 12-bit D/A converter and a power amplifier, and any digital circuits described in 145L
The requirements for your design are:
- The system must record the time for every swimmer to an accuracy of 100 μs even if several swimmers touch their plates in the same 100 μs.
- The lane numbers and time for each swimmer (in units of s) are to be written to the computer display screen and to a file as soon as possible after the swimmer finishes.
a. (30 points) Sketch your design, showing and labeling all essential components and lines. (You only need to show two touch plate switches, timing circuits and speakers.)
b. (30 points) Describe the events (hardware and software) that must take place from the start of the race to after the last swimmer finishes.
3.b (24 points) Design an anti-aliasing filter that meet the above requirements (determine the filter order n and the corner frequency fc)
3. c (24 points) List the steps (hardware and software) involved in sampling the waveform and taking the FFT.
3.d (6 points) To what frequencies do the FFT coefficients H 0 , H 1 , H65,536, and H131, correspond? (See equation sheet for powers-of-two table)
3. e (4 points) If the system input is a pure 1,000 Hz harmonic signal, how would it appear in the FFT coefficients?
3. f (6 points) How close in frequency can two harmonic signals of equal amplitude be and still appear as separate peaks in the FFT?
