Computers as Components, 2nd Edition

7.6 Design Example: Compact DISCs and DVDs 375

analog

radio

A/D DSP

CPU

user

interface

FIGURE 7.15

Baseband processing in cell phones.

Figure 7.15 shows a sketch of the architecture of a typical high-end cell phone.

The radio frequency processing is performed in analog circuits. The baseband pro-

cessing is handled by a combination of a RISC-style CPU and a DSP. The CPU

runs the host operating system and handles the user interface, controlling the

radio, and a variety of other control functions. The DSP performs signal process-

ing: audio compression and decompression, multimedia operations, etc. The DSP

can perform the signal processing functions at lower ...