Similarity To Other Motorola Debugging Firmware; 167Bug Implementation - Motorola MVME167 Series Installation Manual

Debugger General Information

Similarity to other Motorola Debugging Firmware

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167Bug Implementation

4-4
If you have used one or more of Motorola's other debugging
packages, you will find the CISC 167Bug very similar. Some effort
has also been made to make the interactive commands more
consistent. For example, delimiters between commands and
arguments may now be commas or spaces interchangeably.
MVME167Bug is written largely in the "C" programming language,
providing benefits of portability and maintainability. Where
necessary, assembler has been used in the form of separately
compiled modules containing only assembler code - no mixed
language modules are used.
Physically, 167Bug is contained in two of the four 44-pin
PLCC/CLCC EPROMs, providing 512KB (128K longwords) of
storage. Both EPROMs are necessary regardless of how much space
is actually occupied by the firmware, because of the 32-bit
longword-oriented MC68040 memory bus architecture.
The executable code is checksummed at every power-on or reset
firmware entry, and the result (which includes a pre-calculated
checksum contained in the EPROMs), is tested for an expected zero.
Thus, users are cautioned against modification of the EPROMs
unless re-checksum precautions are taken.