ST20–SWC

12/21

3.1

Interactive debugging

Sun-4 or PC host

Target ST20

Debugging

kernel

User

program

Debugger

program

User i/o

debug services

Trace

information

User i/o

server

application

Figure 9

Interactive debugger architecture

The interactive debugger consists of a host-based symbolic debugger and a target-resident debug-

ging kernel that is configured into the application program on an ST20 processor.

The interactive debugger provides the following features:–

A break point facility that can be used on particular threads of execution.

A single stepping facility that allows a thread of execution to be single stepped at the source

level or at the assembly code level.

A watch point facility that enables the program to be stopped when variables are to be written

to or read from.

A facility to find the threads of execution of a program and set break points on them.

A stack trace facility.

A facility to monitor the creation of threads of execution.

Commands to print the values of variables and display memory.

Commands to modify variables and memory at run time.

A simple interpreter to enable C aggregate types (i.e. structures and arrays) to be displayed.

A programmable command language that allows complex break points and watch points to

be set and enables debugging scripts to be generated.

A source and object browser to select a process, a thread and source code.

An interface to the real-time operating system for dynamic code loading and thread creation.