Understanding VHDL-AMS Models

Twin Builder provides several libraries of VHDL-AMS components developed according to IEEE 1076.1 (VHDL Analog and Mixed Signal Extensions Standard) and IEEE 1076 (VHDL standard). These libraries are accessible via the Component Libraries window Components tab.

• The Basic_VHDLAMS library (Basic_VHDLAMS.asmd) contains basic circuit components, blocks, and measurement devices, as well as fluidic, magnetic, mechanical, and thermal components. It also contains a number of time functions.
• The Digital_Elements library (Digital_Elements.asmd) contains basic components commonly used for simple digital circuits (A-to-D and D-to-A converters, counters, flip-flops, latches, gates, and so on).
• The Transformations library (Transformations.asmd) contains auxiliary components (called OmniCasters) that easily connect different data types and natures.

The models provided are open and can be used to derive more advanced models by copying the description to a user library and editing the text to modify the model. You can use and distribute the files if the copyright statement, included in each model description, is not removed. To access the model description, right-click the component name in the Project Manager pane and select View Component Help.

The functionality of all VHDL-AMS models is a subset of the equivalent Twin Builder models available in the Basic_Elements library (Basic_Elements.asmd). You can use VHDL-AMS models in parallel with Twin Builder models.

The digital models operate with digital signals and can be characterized with rise time/fall time/propagation delays. They do not have any conservative nodes but can be connected to analog quantities using OmniCasters (in the Transformations library).