A fusion of digital and analog IC circuits, mixed signal ICs are key components to many applications including IoTs, automotive, communications and consumer electronics –acting as enabler to bidirectional conversion of signals between analog domain derived from various audio, temperature and visual sensors to digital domain of the embedded processing units.
Handoff, DM and integrated SOS7-Tanner benefits
Mixed signal designers typically deal with shorter design cycles as their design will either be an IP of a large SoC or as a stand-alone IC product. In both scenarios, team collaboration and robust handoff mechanisms are needed to ensure a clean integration downstream.
As part of Mentor, a Siemens Business, Tanner EDA provides a list of design, layout and verification portfolio for analog and mixed signal (AMS) ICs, Micro-ElectroMechanical Systems (MEMS), and IoT designs for 28nm and above. As shown in figure 1, the environment consists of schematic and layout capture,
place and route, verification and chip assembly tools –segregated to serve analog, digital or mixed signals centric design.
Integrated into the Tanner design environment is ClioSoft’s SOS7 design management solution that enables local or multi-site design teams to collaborate efficiently on all types of complex SoCs – analog, digital, RF and mixed-signal – from concept-to-GDSII. The three areas DM could help are as follows:
- Improving team efficiency such as access, revision, reuse and release control management. For example, in tracking release versions of an IP, handing-off completed schematic to the layout team for further implementation.
- Automatic, secure and optimal real-time data synchronization across sites and compute resources. For example, design data handoff or sharing to multi-sites can be done automatically without the use of ftp, rsync, cron jobs or other insecure means.
- Design progress monitoring through milestones audit and tracking of any open issues or completed tasks. For example, tracking on which blocks are completed and how many layouts are still pending, all can be done easily.
In order to demonstrate how tightly integrated Cliosoft SOS7 with Tanner design flow, a design involving ADC and DAC components are used. As shown in figure 2, the design data are captured in two ways: for the analog part, DAC, the schematic and layout is captured with SEDIT and LEDIT; while for the digital part, ADC control, a synthesis is involved and followed by layout generation.
Each process refers to its specific libraries (PDK or standard cells) and includes the generation of many views such as schematic, layout, pre- and post-layout netlists. Once the post-layout design verified or simulated, more views are produced such as simulation reports, measurement outputs and output data. In case of SoC design, some of these may need to be propagated further for the validation of overall system.
Without the use of DM, the design database will be a convoluted collection of directories usually in open access (OA), each consisted of many revisions of views and get replicated across into each designer’s local area to track updates –cluttering work area. With SOS7, the design database is captured in common repository along with multiple submitted revisions reducing the overall design footprint. Multi-site teams will be able to streamline design change updates and handoffs. For example a secure reservation of schematic to be worked on can be made, preventing concurrent edits. After each change, auto synchronization across other sites would be made by SOS7 cache server. These help more effective collaboration and also design data management. SOS7 also facilitates IP cataloging, capturing pertinent documentation and propagate any fixes and release to the users connected to the SOS7 Design Collaboration platform. Figure 2 (bottom part) illustrates the comparison before and after SOS7 deployment on the sample case design.
Driving ClioSoft DM in Tanner Environment
ClioSoft SOS7 GUI is invocable from within Tanner tools GUI such as S-EDIT and L-EDIT. As a design cockpit SOS7 GUI provides designers with full visibility of the state of design database such as who is editing which revision of the schematic, when a particular block is done and released, etc.
To enhance team collaboration, some steps such as tagging, labeling and snapshot are recommended during each sub process completion. As seen in figure 4, the use of tagging such as “Design Done”, “Layout Done”, “Design Verified” can be applied to signify milestone completion and inform subsequent users for the state of the database views. Similarly for snapshot as a way to capture all states up to a point (to permit undoing of work if needed).
As part of good design management practices, tracking design collaterals should cover all design related views (including binary format data files), libraries and technology files, runset and documentation. In addition, for verification or simulation related process only limit capture to run summary, logfiles, all used inputs (such as RTL) and testbenches. The remaining large actual simulation and DRC/LVS results as well as intermediate cell views should not be tracked. This will reduce overall project database footprint.
To recap, designers need an effective way to manage their project during the design phase. The integration of ClioSoft’s SOS7 Design Collaboration platform into Tanners IC Design flow allows designers to be more productive. This allows them to focus on their design instead of doing the design data management tasks as well as to facilitate early error findings and fixes –avoiding costly re-design iterations.