Computers as Components, 2nd Edition

8 CHAPTER 1 Embedded Computing

must also perform huge amounts of computation in real time. Not only are cell

phones taking over some PC-oriented tasks, such as e-mail and Web browsing, but

the components of the cell phone can also be used to build non-cell-phone systems

that are very energy efficient for certain classes of applications.

1.1.4 The Physics of Software

Computing is a physical act. Although PCs have trained us to think about computers

as purveyors of abstract information, those computers in fact do their work by

moving electrons and doing work. This is the fundamental reason why programs

take time to finish, why they consume energy, etc.