Motorola MVME166, Installation Manual

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MVME166IG/D24-1
4
USING THE 166Bug
DEBUGGER
Entering Debugger Command Lines
166Bug is command-driven and performs its various operations in response to
user commands entered at the keyboard. When the debugger prompt
(
166-Bug>
) appears on the terminal screen, then the debugger is ready to
accept commands.
As the command line is entered, it is stored in an internal buffer. Execution
begins only after the carriage return is entered, so that you can correct entry
errors, if necessary, using the control characters described in Chapter 3.
When a command is entered, the debugger executes the command and the
prompt reappears. However, if the command entered causes execution of user
target code, for example GO, then control may or may not return to the
debugger, depending on what the user program does. For example, if a
breakpoint has been specified, then control returns to the debugger when the
breakpoint is encountered during execution of the user program. Alternately,
the user program could return to the debugger by means of the TRAP #15
function ".RETURN".
In general, a debugger command is made up of the following parts:
a. The command identifier (i.e., MD or md for the Memory Display
command). Note that either upper- or lowercase is allowed.
b. A port number if the command is set up to work with more than one port.
c. At least one intervening space before the first argument.
d. Any required arguments, as specified by command.
e. An option field, set off by a semicolon (;) to specify conditions other than
the default conditions of the command.