SemiWiki - Custom IC and AMS Tool Flow with Synopsys

The big three EDA companies all have Custom IC and AMS tool flows as shown in the following comparison table:

	Synopsys	Cadence	Mentor
Schematic / Layout	Custom Designer SE Custom Designer LE	Virtuoso Schematic Editor Virtuoso Layout	Pyxis Schematic Pyxis Layout
SPICE Circuit Simulation	HSPICE	Spectre	Eldo Classic Eldo Premier
Fast SPICE	CustomSim	UltraSim	ADiT
Waveform Viewer	Custom WaveView	Virtuoso Visualization	EZ Wave
AMS Simulation	CustomExplorer Ultra	Virtuoso AMS Designer	Questa ADMS
Analysis Environment	Custom Explorer	Analog Design Environment	ICanalyst
DRC / LVS	IC Validator	Assura	Calibre nmDRC Calibre nmLVS
Parasitic Extraction	StarRC	QRC	Calibre xRC
Digital P&R	IC Compiler	NanoRoute	Olympus-SoC Calibre InRoute

I wanted to learn more about the Synopsys tools so I read their recent White Paper: Custom and Mixed-Signal Design Solution.

From a market-share viewpoint the strengths of each EDA vendor are probably:

Synopsys
- SPICE
- Digital P&R tools
Cadence
- Schematic/Layout
- P&R tools
Mentor
- DRC/LVS
- Parasitic Extraction
- AMS Simulation

Schematic Entry and Layout Editing
Schematic entry and layout editing with Customer Designer SE and LE are relatively new EDA tools for Synopsys, and they use the OpenAccess database based on Si2 standards, and work with interoperable PDKs (Process Design Kits) - so you aren't limited to Skill-based Pcells from Cadence. I'm still waiting to hear about the merged product roadmap after the acquisition of: Magma, SpringSoft, Ciranova; here's a blog devoted to the topic.

Design-Rule-Driven Layout
At the 45nm node and below the layout rules have gotten so complex that you can iterate way too many times between your IC layout and DRC tools to get a clean layout, so with SmartDRD you can see DRC violations while doing interactive layout at the cell and block levels, shortening the number of times you need to run DRC in batch.

Digital P&R + Custom Layout
IC Compiler and Custom Designer work together using the same OA database, so no translations or importing steps are necessary.

SPICE and FastSPICE
Synopsys now owns the most circuit simulators out there after acquiring tools from: Magma, Nassda, Avant!. You can even simulate effects like:

Electromigration (EM)
IR-drop
Static and dynamic checks
MOS aging

Violations can be viewing in Customer Designer LE.

AMS Simulation
The transistor-level simulator CustomSim can co-simulate with the HDL simulator VCS, so you can mix and match language-based verification with transistor-level.

DRC / LVS / Extraction
Synopsys has tools for all three categories: DRC / LVS (IC Validator), Extraction (StarRC). Useful debug features like cross-probing between DRC / LVS results and the schematic or layout make life easier for physical verification engineers.

Eating Your Own Dog Food
In EDA this means using your software like an end-customer, so for Synopsys that means that their Analog IP group uses the complete flow of Synopsys tools listed in this blog to design the following:

Conclusion
Synopsys has developed and acquired enough EDA tools to create a complete tool flow for custom IC and AMS design. You can use all their tools together, or mix-and-match with other EDA vendor tools that use the OpenAccess database or de-facto standards (SPICE, iPDK, Verilog, Verilog-AMS, VHDL).