The 8255 Programmable Peripheral Interface is used as described below.

I. An A/D converter is interfaced to a microprocessor through an 8255. the conversion is initiated by a signal from the 8255 on Port C. A signal on Port C causes data to be strobed into Port A.

II. Two computers exchange data using a pair of 8255s. Port A works as a bidirectional data port supported by appropriate handshaking signals.

The appropriate modes of operation of the 8255 for I and II would be

For the circuit shown in Figure, the initial conditions are zeros. Its transfer function $$H(s) = {{{V_c}\,(s)} \over {{V_i}\,(s)}}$$ is

For the lattice circuit shown in Fig., $${Z_a} = j\,2\,\Omega \,\,and\,\,{Z_b} = \,\,2\Omega $$. The values of the open circuit impedance parameters
$$Z\,\left[ {\matrix{ {{Z_{11}}} & {{Z_{12}}} \cr {{Z_{21}}} & {{Z_{22}}} \cr } } \right]\,$$ are

The transfer function $$H\left( s \right) = {{{V_0}\left( s \right)} \over {{V_i}\left( s \right)}}$$ of an R-L-C circuit is given by
$$H\left( s \right) = {{{{10}^6}} \over {{s^2} + 20s + {{10}^6}}}$$

The Quality factor (Q-factore) of this circuit is