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Intr oduction to System-on-Chip (SOC) 61

Time to Volume
Working Development BOM Cost Breakover Time-to-
Silicon Cost Reduction Point market
Non-platform-based 2–3 years $10 million $40 250,000 3 years
90-nm SOC
Cell-based, 6–9 months $4 million $40 100,000 1 year
platform-based SOC

Source: Toshiba America Electronic Components, Inc.

TABLE 2.2 Benefits of Platform-based SOC Design

moves up from just an IP level, which was described earlier, to a HW-SW components
level reuse. On the other hand, one of the key drawbacks of a platform approach is the
need for a larger up-front investment in terms of both the man-month effort required to
deliver a platform as well as the complexity involved. This means that there needs to be
a lot of careful early planning and analysis, particularly at the architectural level. All
hardware and software platform components need to be preverified all the way to
silicon, and this adds to the up-front cost as well. We will describe more of these
challenges and careabouts while discussing design abstraction levels in the next
section.
The platform-based design development working group of the VSIA Consortium
has been working for a while to determine a clear set of platform attributes in order to
provide a definition for the platform taxonomy. The two major kinds that have emerged
are the “application-driven” and “technology-driven” platforms as shown in Figure 2.14.
In the application-driven scenario, different architectural-level families are defined
from certain application domains and a product line family typically gets created. A
top-down process instantiates the required preverified hardware and software IP
modules, and application-specific derivative products are integrated and built on a
single chip. This process is independent of the process technology that is used to build
such systems. In contrast, a technology-driven platform is built bottom-up with the
need to either extend the functionality or performance, or to migrate the design to later
technologies, irrespective of the application requirements.

SOC Verification
The functional verification of an SOC has two components, firstly to verify whether the
implementation meets the specification and secondly to verify that the specification
meets the true intent of the system functionality. Since the system functionality is
realized by the software running on the processors embedded in an SOC, HW-SW
coverification is an important component of SOC verification. In addition to the software
delivered as part of the system solution, the software development environment also
needs to be provided so that customers and users can develop and integrate differentiated,
value-added software. It’s thus important to verify that the appropriate hardware hooks
(for debug for example) required for the software development are functioning as
desired. Figure 2.15 captures the software environment around an SOC with embedded
processor(s). This includes both the software components that run on the SOC and also