$1.$ Explain the differences between using polling and event$-$driven techniques for testing

the state of one of the digital input pins on a microcontroller.

$2.$ List the most significant actions that a CPU takes when it responds to an enabled

interrupt.

$3.$ Explain the following terms with respect to interrupts:

a$.$ Priority

b$.$ Latency

c$.$ Nesting

$4.$ A comparator circuit and LM$35$ are to be used to create an interrupt source, using the

circuit of Fig. $9\mathrm{.}5.$ The comparator is supplied from $5\mathrm{.}0$ V$,$ and the temperature

threshold is to be approximately $38$C$.$ Suggest values for R$1$ and R$2.$ Resistor values

of $470,680,820,1$k$,1$k$2,1$k$5,$ and $10$k are available.

$5.$ Describe in overview how a timer circuit can be implemented in hardware as part of a

microprocessor$$s architecture.

$6.$ What is the maximum value, in decimal, that a $12-$bit and a $24-$bit counter can count

up to$?$

$7.$ A $4\mathrm{.}0-$MHz clock signal is connected to the inputs of a $12-$bit and a $16-$bit counter.

Each starts counting from zero. How long does it take before each it reaches its

maximum value?

$8.$ A $10-$bit counter, clocked with an input frequency of $512$ kHz$,$ runs continuously.

Every time it overflows, it generates an interrupt. What is the frequency of that interrupt stream?

$9.$ What is the purpose of the mbed$$s Real Time Clock? Give an example of when it

might be used.

$10.$ Describe the issue of switch bounce and explain how timers can be used to overcome

this. What is the disadvantage of this approach?