U. Glaeser

FIGURE 42.11 Internet growth.
FIGURE 42.12 Components of a communication SoC.
Advantages of SoCs
The overall size of the end product is reduced because manufacturers can put the major system functions
on a single chip, as opposed to putting them on several chips. This reduces the total number of chips
needed for the end product. For the same reason, the power consumption is reduced.
SoC products provide faster chip speeds due to the integration of the components/functions into one
chip. Many applications such as high-speed communication devices (VoIP, MoIP, wireless LAN, 3G
cellular phones) require chip speeds that may be unattainable with separate IC products. This is primarily
due to the physical limitations of moving data from one chip to another, through bonding pads, wires,
buses, etc. Integrating chip components/functions into one chip eliminates the need to physically move
data from one chip to another, thereby producing faster chip speeds. Another important advantage of
SoCs is the reuse of previously designed circuits, thereby reducing the design process time. This consequently
translates into shorter time-to-market. In addition to decreasing time-to-market, it is very important
to decrease the cost of packaging and testing, which are constantly increasing with the finer technology
features. Instead of testing several chips and the PCB on which they are assembled, testing time is reduced
to only one IC. SoCs are, however, very complex and standards are now being developed to facilitate
their testing [IEEE 1995b]. In the remainder of this paper, we focus on communication systems that we
will refer to as comm. SoC or simply SoC.
Need for Communication Systems
Public switched telephone networks (PSTN) are becoming congested due to increasing Internet traffic
as shown in Fig. 42.11. This drives the development of broadband access technology and high-speed
optical networks. Another important factor is the convergence of voice, data, and video. As a consequence,
there is a need for low and uniform latency devices for real time traffic. In addition, Internet service
© 2002 by CRC Press LLC