Problem: Communicating with I/O devices is achieved using combinations of polling, interrupt handling, memory mapping, and special I/O commands. Answer the questions about communicating with I/O subsystems for the following applications using combinations of these techniques.
1) Auto Pilot
2) Automated Thermostat
a) Describe device polling. Would each application be appropriate for communication using polling techniques? Explain.
b) Describe interrupt driven communication. For each application, if polling is inappropriate, explain how interrupt driven techniques could be used.
c) Does it make sense to define I/O subsystems that use a combination of memory mapping and command driven communication? Explain your answer.