What Is the Difference Between Analog & Digital System Simulation?by Harvey Sells
The continuous nature of analog signals can present challenges in simulation design. The analog signal is also more sensitive to changes in parameters than digital signals. This must be take into account when performing analog simulation.
A major difference that distinguishes analog circuits from digital is that analog circuits are designed in terms of physical performance. Analog circuits do not have gates that can be used to make other devices as in digital circuits. This requires highly complex computations to establish system parameters.
System on a Chip
System on a chip (SOC) is a design where components of an electronic system, such as a computer, are embedded on a single chip. A SOC may be comprised of analog, mixed analog and digital or digital only in a single chip. The presence of analog only or mixed analog and digital chips gives rise to the necessity of simulating all or part of the chip.
Gate-Level Digital Simulation
Digital simulation of analog or mixed-signal chips can be performed using simple digital models. This approach is slow by digital standards and may fail to provide comprehensive coverage of the chip's functions. Additionally, the digital approach can be difficult to correlate with analog behavior. While such approaches show promise of integrating the two technologies, problems will still have to be solved.