Page 67 - System on Package_ Miniaturization of the Entire System

44 Cha pte r T w o

production quickly and also should provide the necessary hooks to be able to
do a quick debug. Most customers also expect that the hardware be bundled
with a reference design, lower-level software drivers, and algorithm kernels so
that it significantly reduces the development cycle time.
6. Application-specific requirements In addition to the above-mentioned
requirements, which generically apply to most applications, there are certain
requirements that are unique to the specific domain.
6.1. Electromagnetic interference (EMI) is a key issue in the automotive market
and also for mobile handsets. These applications require that the radiation
from the device should be under a specified limit and typically specify
frequency bands in which the radiation limits are stringent.
6.2. Soft errors are the transient defects caused during the operation of the
device. The most common form of a soft error is flipping of a memory bit.
The severity of this error can vary depending on whether the impacted
memory contains a program or data. In applications that use a large amount
of memory and have stringent robustness requirements, the soft error rate
(SER) needs to be managed by providing on-line bit error detection and
correction mechanisms.
6.3. The requirement of building lead-free devices is driven primarily by
environmental considerations and is increasingly becoming a mandatory
requirement across most markets—especially in Europe and Japan. This
primarily drives changes in the packaging technology where the bumps
with lead content have been used as they enable processing at a lower
temperature than the lead-free bumps.
6.4. Automotive applications demand systems to have near-zero defective
parts per million (DPPM). With the complexity of systems going up both
in terms of number of transistors and performance, achieving 0 DPPM is
getting increasingly challenging.
6.5. For mission-critical applications and also infrastructure-type applications
with stringent downtime requirements, fault tolerance is an important
requirement. Fault tolerance is the ability to detect faults (either transient
or permanent) occurring while the device is in operation and the ability to
continue to function correctly in the presence of the fault. The fault tolerance
requirements are typically addressed by providing redundancy at the SOC
and/or at the system level.

2.3 SOC Architecture
Figure 2.4 shows a generic SOC architecture in terms of the key building blocks. These
include embedded processor core(s) with associated data and program memory,
application-specific hardware accelerators and coprocessors, customer-specific IP,
industry-standard interfaces, external memory controllers, and analog or RF IPs.
SOCs address the key customer requirements through the following:
1. Level of integration Because SOC involves integrating multiple chips on a
single device, the cost of the single device is typically less than the cost of
multiple chips. Since it reduces the number of devices on the board, the resultant