More than a microprocessor
, a System on Chip (SoC) is an integrated circuit
where all of the subsystem
s involved are on a single piece of silicon
. For example, an FM radio requires a tuner
, an amplifier
, and a power management
circuit. Prior to the development of SoCs, one would need an microchip
for each portion of the entire circuit, and they would be soldered
on a printed circuit board
that would make up the core of the device.
Advances in miniaturization and chip design have enabled the entire circuit to be placed on a single microchip. This integration has occurred in many application areas, from the aforementioned radio-on-chip to such complex devices as a camera-on-chip, which integrates on the same piece of silicon the image sensor and all related signal processing circuitry. That's why you can buy a cell phone with a camera in it today.
There is even research going on now (early 2003) using continuous-grain silicon that will enable the creation of System LCDs (SLCDs) that integrate all driver and operation circuitry--including digital logic, LCD driver, power supply, I/O interfaces, and signal-processing circuitry--onto the glass itself. Imagine a credit-card-sized PDA where the entire surface is a touchscreen display.