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IEEE 1076.1-Analog & Mixed-Signal

Analog extensions to VHDL


VHDL-AMS provides extensions to VHDL for simulation of analogue and mixed-signal systems. It is built on IEEE Std 1076-1993 and extends it with additions to provide capabilities for writing and simulating analog and mixed-signal models. Work started in 1989 with the 1076.1 subgroup being formed in 1993 under the DASC. It was first approved as a standard in 1999.

The language supports several abstraction levels in electrical and nonelectrical energy domains. The modeled analog systems are lumped systems that can be described by ordinary differential equations and algebraic equations. The language does not specify any particular technique to solve the equations, but it rather defines the results that must be achieved. The solution of the equations may include discontinuities.

Interaction between the digital part of a model and its analog part is supported by a unified model of time between the event-driven and continuous behavior. It also includes frequency domain support.

VHDL-AMS introduced the notion of quantities that are related to physical effects. Two quantities are defined: Across for effects such as voltage, velocity and temperature and Through for effects such as current, force, heat flow etc. Each of these can have a specified tolerance used to specify how accurate the simulation needs to be.

The System Designer’s Guide to VHDL-AMS: Analog, Mixed-Signal, and Mixed-Technology Modeling (Systems on Silicon)

The VHDL Reference: A Practical Guide to Computer-Aided Integrated Circuit Design including VHDL-AMS