Altair's SpiceVision PRO - Helping chip designers at the SPICE level.
Altair EmployeeAltair's SpiceVision PRO - Helping chip designers at the SPICE level.
Introduction-
SPICE (Simulated Program with Integrated Circuit Emphasis) is an open-source analog electronic circuit level simulator. SPICE circuits and models are common in the Electronic Design Automation (EDA) world. They are generated by many EDA tools and describe the circuit at the lowest component abstraction level, the transistors, capacitors, resistors, and even the interconnect that make up an IC or IP component. But for all but the most trivial designs, SPICE files are very difficult to read and understand. The purpose of this blog is to provide an overview of Altair’s SpcieVision PRO tool and how it can help designers in the chip design process.
SpiceVision PRO automatically generates visual circuit schematics, accelerates debugging, and helps to solve design problems in Digital Circuits, Mixed-Signal ASICs, Analog Circuits, Printed Circuit Boards, and MEMS. SpiceVision PRO takes SPICE netlists and models and generates clean, easy-to-read transistor-level schematics, circuit fragments, and design documentation to speed up circuit design, debugging, and optimization at the transistor level.
Figure 1. SpiceVision PRO UI.
Schematic generation-
SpiceVision PRO reads the SPICE files generated by some popular and commonly used simulators in the industry to generate a nice and human readable transistor level schematic. The following table shows the list of formats the tool can read and generate schematic from.
| SpiceVision PRO | SPICE, HSPICE, Spectre, Calibre, CDL, Eldo and PSPICE |
| Parasitic Analysis Package | DSPF and SPEF |
| Analog Waveform Viewer | TR0, AC0, SPI3 and PSF. |
Table 1. Supported file formats by Altair’s PRO.
Within seconds, SpiceVision PRO gives engineers an extra level of understanding of the circuits that are defined in their SPICE netlist file. The tool provides the unique and effective graphical rendering of SPICE netlists and supports engineers to debug and optimize designs, moving devices into production earlier and with a higher degree of confidence. The following example shows an HSPICE netlist read by the tool to generate a transistor-level schematic of a NAND sub-circuit. The highlight feature allows to color code elements in the circuit for cross probing with the netlist file. In figure 2, two transistors were highlighted (red and green). These colors are also reflected in the spice netlist located at the bottom of the interface.
Figure 2. Schematic generation using hspice netlist.
Another great feature SpiceVision PRO has is that it allows users to switch modes between analog and digital views of the schematic. This eases the debugging process while dealing with mixed-signal designs.
Figure 3. Instant switch between analog and digital view of the schematic.
Interface with Cadance Virtuoso-
Cadence Virtuso is popularly used in the IC design world. Using the Cadence SKILL language and Virtuoso schematic editor option SpiceVision PRO can automatically generate critical path schematics or schematics of larger IP blocks using netlist information. It allows users to export these schematics into the Cadence schematic editor environment for further editing, IP reuse, or simulation. For the designers who are using the Candance Virtuso design tool the skill export feature of SpiceVision PRO allows them to export the generated schematic directly to Virtuso hence saving the time and effort needed to draw the schematic.
Figure 4. Skill export.
Incremental schematic generation-
SpiceVision PRO has a great feature called incremental schematic navigation which allows the user to extract a critical portion of the circuit into the cone window of the tool. This feature allows users to concentrate on critical circuit fragments, with links to the original SPICE source code, while ignoring irrelevant design areas. This highly interactive view allows engineers to automatically build up critical paths through a design to rapidly find bug drivers. Complex bugs may be located and fixed quickly and easily. Circuit fragments displayed in the cone window can easily be exported to a simulator as separate SPICE files (SPICE netlist export), for partial simulation, often running 10 to 100 times faster than the full circuit simulation.
Figure 5. Cross-probe between schematic and cone window.
Parasitic analysis-
Altair’s SpiceVision PRO can also be helpful in post-layout debugging, and IP verification and reuse. For post-layout debugging, the layout parasitic extraction (LPE) tools generate a large and complex netlist. The parasitic window of SpiceVision PRO allows visualization and analysis of the parasitic networks. The tools allow users to read DSPF and SPEF file formats and provide capabilities to prune and export SPICE, DSPF or SPEF netlists for fast critical path simulation. For IP verification and reuse specific parts of a design can be extracted from the complete design and saved as a separate SPICE netlist for use as new IP or for detailed SPICE simulation.
Figure 6. Parasitic analysis using SpiceVision PRO.
Waveform analyzer-
SpiceVision PRO offers integrated analog waveform viewing as an option. The analog waveform viewer allows design engineers to see the signal transitions over time and the relation of those signals with other signals in a design. Using signal drag and drop between the schematic window and the waveform window allows easy signal tracing and detection of simulation problems.
Figure 7. Waveform window.
Apart from all these features mentioned in this blog Altair's SpiceVision PRO ships add-ons/plugins which are customized scripts written to perform specific tasks these scripts are editable and can help designers in writing their tests for the design.
Conclusion-
For chip designers SPICE netlists in analog, digital and mixed-signal design can be very complex to read and debug. If not done carefully this can lead to malfunction and even failure of the device in advanced stages of design and even after design stages. Altair's SpiceVision PRO is a tool that provides users an environment to analyze and debug SPICE netlist generated by some of the most popularly used simulators in the industry thereby, allowing users to analyze and correct any issues at the earliest design phase. This blog provides a high-level overview of Altair's SpiceVision PRO covering the basic and necessary features in SPICE netlist analysis and debugging to learn more about the tool visit https://altairone.com/Marketplace?tab=Info&app=Silicon+Debug+Tools