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Debugger General Information
3
Models with no VMEbus interface have a jumper between
pins 7-8 as well.
These readable jumpers are read as a register (at $FFF4202D)
on the Memory Controller (MC2chip) ASIC. The bit values
are read as a zero when the jumper is installed, and as a one
when the jumper is removed. This jumper block (header J21)
contains eight bits. Refer also to the MVME162LX Embedded
Controller Programmer's Reference Guide for more information
on the MC2chip.
The MVME162Bug reserves/defines the four lower order bits
(GPI3 to GPI0). The following is the description for the bits
reserved/defined by the debugger:
Bit J21 Pins Description
Bit #0 (GPI0) 1-2 When set to 1 (high), instructs the debugger to
use local Static RAM for its work page (i.e.,
variables, stack, vector tables, etc.).
Bit #1 (GPI1) 3-4 When set to 1 (high), instructs the debugger to
use the default setup/operation parameters in
Flash or ROM versus the user setup/operation
parameters in Non-Volatile RAM (NVRAM).
This is the same as depressing the RESET and
ABORT switches at the same time. This feature
can be used in the event the user setup is
corrupted or does not meet a sanity check. Refer
to the ENV command (Appendix A) for the
Flash/ROM defaults.
Bit #2 (GPI2) 5-6 Reserved for future use.
Bit #3 (GPI3) 7-8 When this bit is a zero (low), it informs the
debugger that it is executing out of the Flash
memories. When this bit is a one (high), it
informs the debugger that it is executing out of
the PROM.
Bit #4 (GPI4) 9-10 Open to your application.
Bit #5 (GPI5) 11-12 Open to your application.
Bit #6 (GPI6) 13-14 Open to your application.
Bit #7 (GPI7) 15-16 Open to your application.