Preserving the Debugger Operating Environment
4-13
4
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 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
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 MC2chip.
2. This depends on what the Vector Base Register (VBR) is set to in the VMEchip2.
To Next Page
Loading...
Need help?
General
