EECS 373 F99 Notes 12-1 © 1999 Steven K. Reinhardt
Wrap-up
Two different types of microprocessor-based systems:
•general-purpose
•embedded: dedicated to a specific task as part of a larger
product
Those of you who work in this area are much more likely to end
up in the latter field. Contrast ~80 million PCs, few million
servers/mainframes etc. with over 3 billion embedded systems
per year (1995 data).
Categories of embedded systems:
•general: thinly veiled, somewhat specialized computers
•video game console
•WebTV box
•info kiosk
•control: feedback control of physical systems
•vehicle engines
•manufacturing (milling machines, assembly line)
•aircraft flight control
•signal processing: high-bandwidth data stream manipulation
•filtering, analysis, compression, decompression
•radar, modems, medical imaging,
•communications/networking
•telephone switches, network routers, voice-mail systems
Many systems will have incorporate facets of more than one
category.
General-purpose systems:
•performance, cost are primary goals
•often shoot for max performance at given price point
•processor (and often peripheral) choices dictated by
software compatibility
Embedded systems:
•cost is usually paramount (even for NASA)
•must meet functional requirements at minimum cost
• must consider system cost:
•CPU, memory, I/O devices
•integrated microcontroller is usu. best bet if capable
enough
•circuit board size (smaller is cheaper)
•connectors
• power supply (# of batteries, AC adapter req’d?)
•software development cost (non-recurring engineering
(NRE), but may be largest single item)
•life-cycle issues:
•manufacturing cost
•testability
•maintenance: availability of spare parts, ease of
repair/upgrade
