The Analog, Mixed-Technology and Mixed-Signal HDL for Saber 


  • Create analog, digital or mixed-signal models and designs
  • Integrate multiple technologies, seamlessly
  • Draw on thousands of currently available models
  • Easily exchange models with customers, ASIC vendors and colleagues
  • Perform statistical analysis with built-in features that embed real statistical data into your models

The MAST Hardware Description Language (HDL) from Synopsys is the defacto industry standard. First released in 1986, MAST is the most advanced modeling language available for analog, mixed-signal and mixed-technology applications.

Until the advent of MAST, developing analog behavioral models was only within the realm of a few individuals - those with expertise in low-level simulator details and those with an in-depth understanding of macro-modeling techniques. Today, MAST has revolutionized the analog simulation industry by providing a methodology in which models can be created - and maintained - by users as well as their IC suppliers, ASIC vendors or EDA tool providers.

Complex Modeling Made Easy
The rich set of modeling constructs available in MAST allows you to model both analog behavior and event-driven behavior as demonstrated in a pulse width modulator or a voltage comparator. This truly makes MAST a mixed-signal hardware description language.

MAST lets you model complex electrical circuits quite efficiently. It also has a well-defined interface that lets you access C++ and FORTRAN routines from within a model, allowing you to readily reuse existing models. Many models, like the BSIM models from UC Berkeley, the TOM GaAs MESFET model from Triquint Semiconductor, and numerous other proprietary MOSFET, MESFET and bipolar transistor models, have now been ported to MAST via this mechanism.

MAST lets you make extensive use of hierarchy when developing models, which further encourages model reuse. MAST also possesses many advanced features that allow you to specify information like stress measures and statistical variations on parameters.

Model Electrical and Non-Electrical Technologies
MAST revolutionized analog simulation by adding the capability to model non-electrical technologies as well. Other technologies modeled in MAST include thermal, mechanical, hydraulic and optical systems. Furthermore, s-domain and z-domain models can be represented in MAST for use in mathematical modeling of components or systems. These other technologies can be described in their native units where results from simulation will preserve the physical units of the technology you are modeling in. These robust capabilities let you model mixed-technology applications such as:

  • Power Supplies
  • Analog/Digital ASICs
  • Electro-hydraulic, Anti-lock Braking Systems
  • Motion Control Systems

With MAST, Synopsys has created an extensive library of analog and mixed-signal models ready for your use.

Synopsys' libraries consist of models in all of the above-mentioned technologies, including motors, self-heating semiconductor power devices, rotational and translational mechanical devices, discrete electrical devices and other innovative models.

Models for the Masses
Since MAST models are ASCII files, instead of compiled code, you can easily exchange or share them with colleagues on other supported hardware platforms. This capability is particularly important as the design process becomes increasingly decentralized. With MAST, models can be readily distributed within your organization, to strategic partners, sup-pliers or subcontractors, via electronic mail or through bulletin board services. Additionally, MAST models can be encrypted for model security.

Modeling Made Easy
MAST lets you model your devices in the most efficient and productive way, making your models inherently faster and more useful. The following are a few examples of MAST's powerful capabilities.

Device Modeling
Accurate device models require accurate mathematical descriptions. As a simple example, Ohm's law describes the behavior of an ideal resistor as:    v=i*r

Using MAST, a model for the resistor can be quickly and easily written. (See example 1)

Using MAST, a model for the resistor can be quickly and easily written

The three equations comprising the body of the model specify relationships, not assignments. Because of this equation-based format, models are as easy to modify as they are to create and use. For example, you can quickly add temperature effects to the resistor model. (See example 2)

See example 2 of MAST

Statistical Modeling
Unlike the Verilog-A or Verilog-MS proposed standards, MAST provides built-in features for statistical analysis. Device parameters can be assigned using a broad range of predefined or custom distributions and correlations. Once assigned, these parameters can be varied statistically using Saber's Monte Carlo analysis, available in the Saber InSpecs add-on package. Example 3 models a resistor and capacitor in series. The resistor's value is assigned a uniform distribution with user-defined upper and lower bounds, while the capacitor's value is given a normal distribution with a user-defined tolerance.


Graphical Modeling
Graphical Modeling is a fast method for creating your own MAST models. Using existing MAST templates as building blocks, you can quickly construct composite models without coding directly in MAST.


For this example we will create a simple Voltage Clipper model designed to provide clipping at +/- 12 volts. Following our three-step process, we first place a Non-Linear Function symbol in the schematic (Example 1). In the property list for the symbol, we then enter the defining equation for the clipper (here we will use vout = if vin < -12 then -12 else if vin > 12 then 12 else vin). After finishing the schematic we complete the process by simulating the design. During simulation the Voltage Clipper model is automatically generated (Example 4). This model file is independent of the simulation and can be reused in other circuits.

MAST HDL is included with the Saber Mixed-Signal Simulator

Platform Support
Popular Unix, Linux, and Windows Platforms Supported

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