Motorola MVME162 Manuale Utente

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Preserving the Debugger Operating Environment
MVME162IG/D2
4-11
4
Exception Vectors Used by 162Bug
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.
When the debugger handles one of the exceptions listed in Table 4-2, the target 
stack pointer is left pointing past the bottom of the exception stack frame 
created; that is, it reflects the system stack pointer values just before the 
exception occurred. In this way, the operation of the debugger facility 
(through an exception) is transparent to users.
Table 4-2.  Exception Vectors Used by 162Bug
Vector
Offset
Exception
162Bug Facility
$10
Illegal instruction
Breakpoints (used by 
GO
GN
GT
)
$24
Trace
Trace operations (such as 
T
TC
TT
)
$80-$B8
TRAP #0 - #14
Used internally
$BC
TRAP #15
System calls
$NOTE 1
Level 7 interrupt
ABORT pushbutton
$NOTE 2
Level 7 interrupt
AC Fail
$DC
FP Unimplemented Data Type Software emulation and data type 
conversion of floating point data.
NOTES:
1.
This depends on what the Vector Base Register (VBR) is set to in the 
MCchip.
2.
This depends on what the Vector Base Register (VBR) is set to in the 
VMEchip2.