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
• Turn the green LED OFF
• Turn the yellow LED ON
• Turn the yellow LED OFF
• Turn the red LED ON
• Turn the red LED OFF

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.