Examples; Hardware Functions; Exception Vectors Used By 167Bug - Motorola MVME167 Series Installation Manual

Examples

Hardware Functions

The only hardware resources used by the debugger are the EIA-
232-D ports, which are initialized to interface to the debug terminal
and a host. If these ports are reprogrammed, the terminal
characteristics must be modified to suit, or the ports should be
restored to the debugger-set characteristics prior to reinvoking the
debugger.

Exception Vectors Used by 167Bug

The exception vectors used by the debugger are listed below. These
vectors must reside at the specified offsets in the target program's
vector table for the associated debugger facilities (breakpoints,
trace mode, etc.) to operate.
Vector
Offset
$10
$24
$80-$B8
Preserving the Debugger Operating Environment
If, for example, your program inadvertently wrote over the
static variable area containing the serial communication
parameters, these parameters would be lost, resulting in a
loss of communication with the system console terminal.
If your program corrupts the system stack, then an incorrect
value may be loaded into the processor Program Counter
(PC), causing a system crash.
Table 5-2. Exception Vectors Used by 167Bug
Exception
Illegal instruction
Trace
TRAP #0 - #14
167Bug Facility
Breakpoints
(used by GO, GN, GT)
Trace operations
(such as T, TC, TT)
Used internally
5
5-13