Taking a Look Inside a System on Chip (SOP)

Embedded platforms were initially composed of separate discrete components. The processor was a separate component with just a memory bus interface, and all peripherals were attached to this bus. As integration levels increase, more and more logic is added to the processor die, creating families of application-specific service processors. The term system on chip (SOC) is often used to describe these highly integrated processors. These SOCs include much of the logic and interfaces that are required for a range of specific target applications. The silicon vendors that develop these SOC devices often create families of SOCs all using the same processor core, but with a wide range of integrated capabilities.

SOCs integrate capabilities to connect the SOC to external memory devices and nonvolatile storage devices using glue-less interfaces. Glue-less is a term used to indicate that there is no additional logic needed to connect the two devices, for example, connect the SOC to DDR DRAM. In addition to attaching to memory devices, an SOC provides segment- or application-specific interfaces. Examples of integrated devices are general purpose input/output pins, interfaces such as Ethernet, USB, PCIe, serial ports, I2C, expansion parallel buses, and integrated display controllers. Many of these devices interface to nonvolatile storage such as NOR Flash via Serial Peripheral Interconnect (SPI), and native bus interface types. As a general rule, these integrated items are predominantly digital logic elements. Because we need to add analog capabilities, features such as flash memory and digital/analog converters are common, but these capabilities require special features of the silicon manufacturing process.
The number one advantage of an S...

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...t categories ranging from consumer devices to industrial systems:

• Cell phones use several programmable processors to handle the signal processing and protocol tasks required by telephony. These architectures must be designed to operate at the very low-power levels provided by batteries.
• Telecommunications and networking use specialized systems-on-chips, such as network processors, to handle the huge data rates presented by modern transmission equipment.
• Digital televisions and set-top boxes use sophisticated multiprocessors to perform real-time video and audio decoding and user interface functions.
• Television production equipment uses systems-on-chips to encode video. Encoding high-definition video in real time requires extremely high computation rates.
• Video games use several complex parallel processing machines to render gaming action in real time.