CSC270 Homework 8 2016

--D. Thiebaut (talk) 14:00, 31 March 2016 (EDT)

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This homework can be done in pairs. It is due on Thursday 4/7/16 at 23:55 p.m. Submit a pdf with your answer on Moodle.

Problem #1

Design an I/O port that controls 3 LEDs. One is green, one is yellow, and one is red. They are used to control the traffic at some intersection. Typically, green is ON for 3 seconds, then it goes OFF and yellow turns ON and stays ON for 1 second. When yellow turns OFF, red turns ON for 3 seconds, and the cycle of green/yellow/red activation repeats.

Question 1: logic design

Provide a logic design that would work with the current 6811 kit (actually, you could wire it up to verify that it works). Show the 6800, a decoder, and the hardware that activates the 3 LEDs.

Question 2: driver

Show the set of instructions you can use to

• Turn the green LED ON (and leave the others in the state they were in)
• Turn the green LED OFF (and leave the others in the state they were in)
• Turn the yellow LED ON (and leave the others in the state they were in)
• Turn the yellow LED OFF (and leave the others in the state they were in)
• Turn the red LED ON (and leave the others in the state they were in)
• Turn the red LED OFF (and leave the others in the state they were in)

Question 3: software loop

Show the assembly language program that implements the 3 seconds green, 1 second yellow, and 3 seconds red cycle.

Problem #2

We want to use the 6811 kit to generate a series of pulses (1-0-1-0-1-0-1-...) as fast as possible. We want these 1-0-1-0 transitions to activate some device, and we are interested in the fastest transmission rate possible.
We want to send 100 bits: 50 0s and 50 1s: 010101010101010101...01
Propose a hardware and software design that will provide the fastest possible transmission of these 100 bits.
Your grade for this problem will be based on 1) the feasibility of your design, and 2) the transmission speed it allows.