An integrated circuit is configured to receive encoded digital data from a system
controller over a single signal line. The system controller encodes the digital
data into a singular analog quantity such as a voltage, a current, a sine wave
frequency, a sine wave amplitude, a pulse train frequency, or a pulse train duty
cycle. The encoded digital data is transmitted to the signal line. The integrated
circuit decodes the digital data from the signal line. The decoded digital data
is employed by the integrated circuit to adjust one or more parameters of the integrated
circuit. In one example, one or more parameters may be adjusted to select various
operating modes for the integrated circuit. The singular analog quantity encoding/decoding
methodology may be extended to more than one signal line when desirable.