Technical Publications

VHDL-AMS (IEEE Standard 1076.1) provides hardware modeling capabilities that are well suited for CAN signal integrity analysis. This includes modeling the analog, digital and mixed-signal aspects of the transceivers, as well as the behavior of twisted-pair transmission lines, connectors and other components of the CAN Physical Layer. SystemVision supports both VHDL-AMS as well as traditional Spice modeling methods. This paper presents various modeling approaches applicable to the key hardware components of a CAN bus. It also provides examples of simulation-based techniques for CAN signal integrity design.

The functionality and performance of modern military and aerospace systems has become heavily influenced by their electronic content. Consequently, selecting the right electronic components and choosing the optimal design methodology is vital in developing a successful product. The flexibility and capabilities of new digital components is still growing exponentially. The potential of these devices, however, cannot be fully (and safely) utilized without incorporating the latest design and verification methodologies. Design methodologies for mil-aero applications must consider the complexities of mechatronic systems. The VHDL-AMS language is an undiscovered asset for mil-aero digital designers - a powerful tool to define and verify safety-critical requirements in a non-digital context. This paper discusses the use of VHDL-AMS for safety-critical digital systems.

Lit Number: TECH7810-w

A versatile new modeling technology was used to help design an innovative traction control system. Using models written exclusively in the IEEE standard VHDL-AMS language, simulation-based analysis and verification were performed at both the component/subsystem and at the overall system levels. Key insights were gained about a wide range of design issues, from the critical need to bleed the brake lines, to power converter topology trade-offs, to detecting inherent wheel lock-up modes in the control algorithm. This paper presents modeling and simulation techniques applicable to a wide range of automotive "mechatronic" systems, where coordinated interaction of mechanical, electronic, and software components is required to meet performance goals.

This paper shows how the IEEE Standard 1076.1 (VHDL-AMS) hardware description language was used to create versatile models of LVDT and RVDT sensors. These models can be used to support the design or selection of suitable signal conditioning circuits or algorithms for specific applications. Signal conditioning is a key aspect of LVDT and RVDT sensing systems, with a strong impact on meeting measurement accuracy requirements. In the design example, the effects of a long cable, between a remote LVDT sensor and its associated signal conditioning circuitry, are examined. Measurement error due to cable length and temperature changes, as well as signal conditioning circuit variations, is analyzed. The design process leverages SystemVision's parametric analysis capability to make important signal conditioning and system design trade-offs.

The IEEE Standard 1076.1 (VHDL-AMS) provides hardware modeling
capabilities that are well suited for Controller Area Network (CAN)
signal integrity analysis. This includes modeling the analog, digital
and mixed-signal aspects of the transceivers, as well as the behavior of
twisted-pair transmission lines, connectors and other components of the
CAN Physical Layer. This paper presents various modeling approaches
applicable to the key hardware components of a CAN bus. It also provides
examples of simulation-based techniques for CAN signal integrity design,
including:

• Analyzing static and dynamic features of transceivers, lines and
  other components
• Examining termination strategies
• Characterizing data delay vs. intermediate-node stub-length
• Assessing Electrostatic Discharge (ESD) protection capability of
  Transient Voltage Suppression (TVS) components

Mechatronic system designs are complex by nature, and are becoming more so all the time. Not only has the typical system design grown in overall size to accommodate ever-increasing demands for functionality and performance, but these designs must fluently integrate analog and digital hardware, as well as the software that controls it. This has presented daunting challenges for design teams. And at the same time design teams are scrambling to keep up with these new challenges, there is increased pressure to reduce development cycle time.

In order to keep pace with these new realities, new processes and development tools are required. In particular, the development and intelligent use of computer models of these complex systems--once considered a luxury--are becoming critical components to the success of the overall development process. This paper presents a brief introduction to the development of mechatronic system models for computer simulation and analysis.