Overview

Chapter 6 introduced the three key capabilities necessary to hardware/software (HW/SW) integration:

• Microprocessor run control

• Memory substitution

• Real-time trace

So far, you ve learned how to address these capabilities using separate tools, namely a debugging kernel, a ROM emulator, and a logic analyzer. In this chapter, you ll see what happens when you design a tool system that addresses these needs in a more integrated fashion.

Traditionally, an in-circuit emulator (ICE) is a single-test instrument that integrates all these functions and more. (Modern on-chip debugging support has changed this somewhat, as the later sidebar Distributed Emulators explains.) Emulators are the premier tools for HW/SW integration. An emulator s close coupling of run control, memory substitution, and trace facilities generates a synergism that significantly increases the power of each component.

Even so, the ICE is widely underused. Only about one-third of the embedded system designers, principally firmware developers, use ICE tools. Hopefully, after reading this and the next chapter, you ll appreciate how important the ICE is to HW/SW integration.

Bullet-Proof Run Control

In the most general case, an ICE uses a debug kernel for run-time control but with a difference that eliminates dependence on the target s untested memory/processor interface. Instead of relying on the...