Planning And Communication Tool For Early Stage LSI-Package-Board Co-Design
Typical screenshot of GemPackage. The product designer studies the ASIC pin assignments in board level, and put a memo for an improvement.
GemPackage has three major features.
- Early Stage Planning Functions
- Communication Aids With Design History Sharing
- Database Security Protection
- Front Loading In Your Product Development Process
- Creativity And Innovation In Product Concept
- Speeding up Product Launching
- Avoiding Risks of Implementation Failures
Semiconductor and electronic products have evolved in the 20th century by introducing the horizontal division of labors. However in 21th century, several factors appeared and the simple don’t-care-beyond-the-boundary strategy does not work anymore. There are four common types of co-designs today.
Co-Des I: IC Package Prototyping
System-in-Package and Package-on-Package became popular for IC package structure, after the flip phones and digital still cameras appeared. It brought a sudden increase in IC package design cases. IC package houses supply the major design power, but they usually cannot provide feasibility study service, i.e. determining if the design being possible or not quickly without actually engaging the design. Then the IC package designers in the semiconductor suppliers have to perform the feasibility study themselves. Later, as the the signal speed increase, SI/PI issues are added in the phase, which changed the name from feasibility study to IC package prototyping. GemPackage has proven usefulness for IC package prototyping with the unique rats-bending based routability study function, the user-friendly wire bonding planning function, and many others.
Co-Des II: Chip/Package Co-Design
As the signal become faster and dimmer, the chip does not work correctly if the chip pins are assigned arbitrary and then routed to package pins in a spaghetti-like detoured paths. Dedicated routing techniques have been applied in the IC package and in the mother board, e.g. differential-pair parallel routing and equi-length routing, but they are essentially for local adjustment. In the end, the chip IO designers and the IC package designers should work together to determine the IO placement and IC package routings together. GemPackage has been used for the chip/package co-design because of the IO cell planning feature and the super-hierarchical nature of the database.
Co-Des III: Platform Planning
Signals are getting faster and dimmer further, which makes system houses to face against the problems such as unplanned noise components needed at final stage, or board layout change in a worse case, if they were not careful about their chip. The SI/PI/Thermal simulation have to be adopted but sometimes it is too late because the chip is designed far earlier. To solve the problem, system houses need to start very early board planning for their next generation products, with the next generation ASIC chip. The input information would be not sufficient; some parts are bogus or missing, pin assignments are free, etc. However, if studying well, they become able to ask more specific requests to semiconductor suppliers, for example simulation models, decap requests, and pin assignment, when they actually engage the development of their new chip. GemPackage supports such platform planning, by providing methods for netlist generation based on floorplan (different from traditional netlist based floorplan), considering power integrity far before plane generation, easy-to-use on the fly parts generation, etc.
Co-Des IV: System/Semiconductor Co-Design
Early stage planning, such as platform planning, is usually done internally in a company. If it can be done by inter-company collaboration, it will bring new level of benefits. For example, if the system house provide concept phase board layout to semiconductor supplier, the semiconductor supplier can consider it in the initial offer of the pin assignment. If the semiconductor supplier provides the prototype phase IC package layout data to the system house, the system house can simulate SI/PI before the CAD phase. Such big enhancements in the early concept phase realizes a big front loading in your product design process. The merits are (1) innovative products because of the enhanced concept phase, (2) speed-up in product launching, and (3) avoiding risks in later phase. The key to the inter-company co-design in concept phase is in the communication, management, and security issues, rather than in the technical issues. For example, design history is hoped to be shared by all the co-design member companies, but their internal communications have to be hide from others. A company may not want to provide their data if there is no systematic mechanism to prevent unexpected use of the data. GemPackage provides good communication, management, and security functions to support system-house/semiconductor-supplier co-design in concept-phase.
The merits of the front loading are summarized as follows.
- Enforce creativity and innovation in product concept
- Speeding up the product launching
- Avoiding risks of production failures in later phases.
Challenges In Front Loading
System house is the leader in the co-design team in typical cases. The leadership is needed to involve necessary partners in earlier phase. Then, the system house need to provide early planning information to the partners, as openly as possible, even though it is immature state.
Semiconductor engineers in the team must pay attentions to board level layout from the start of the co-design project, not only coordinating the consistency in chip/package level co-design in the semiconductor company. Once they have a feasibility study level layout in IC package, they better provide the data to the system house, so that the system house can carry out preliminary simulations. In providing IC package level data to system house, they are allowed to restrict the use of the data only for concept phase. That is, system house may not transfer the concept phase to design phase based directly using the data, without the consent of the semiconductor supplier. Such security consideration is necessary in system/semiconductor co-design.
EDA has been focusing in design functions, and the users were responsible for the purpose to use it for. However, in the system/semiconductor co-design, they need different functions in EDA tools. First, EDA need to supply early stage planning functions, operable and useful with the fewest input data. EDA also need to supply data exchange and communication functions. Finally, EDA need to have functions to protect rights of the co-design member companies. These points are well addressed in GemPackage because we have been working with top edge customers.
EDA Challenges In System/Semiconductor Co-Design
Very Early Stage Planning Functions
The concept phase starts with the fewest information, then EDA must supply functions to start planning from scratch, then it must be able to capture more information seamlessly as the planning evolves. Typical requests are as follows.
- Optimize Floorplan Without Netlist
- Examine Routability Without Actually Routing
- Care Power Integrity WIthout Making Power Planes
Data Exchange and Communication Aids
EDA has been paying too little about data exchange and communication, comparing to the office tools. The minimum requirements are as follows.
- EDA-Brand Independent Database Sharing
- Message Exchange Without Cut-and-Paste Tool Screen
- Design History Sharing In Co-Design Team
Database Security For Idea Protection
Co-design members cannot share their ideas with other members, even though they personally wish, if their ideas are not protected right. They can have non disclosure agreement before starting the collaboration, but that is not persuasive enough in the company. More systematic mechanism is necessary. The requests are as follows.
- Hide Internal Records In Design History Sharing
- Prohibit Unexpected Use In Database Sharing