Motorola MVME162LX User Manual

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162Bug Implementation
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162Bug Implementation
MVME162Bug is written largely in the ÔÔCÕÕ 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 Ñ no mixed 
language modules are used. 
Physically, 162Bug is contained in a single 27C040 DIP EPROM 
installed in socket XU2, providing 512KB (128K longwords) of 
storage. As an option, the 162Bug firmware can be loaded and 
executed in a single Flash memory chip. 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 
memory devices), is tested for an expected zero. Thus, users are 
cautioned against modification of the memory devices unless re-
checksum precautions are taken. 
Installation and Startup
Follow the steps below to operate 162Bug with the MVME162LX 
module. 162Bug is factory-installed in EPROM, except in the no-
VMEbus case.
!
Caution
Inserting or removing boards while power is applied 
could damage board components.
1. Turn all equipment power OFF. Refer to the Hardware 
Preparation section in Chapter 2 and install/remove jumpers 
on headers as required for your particular application.
Jumpers on header J21 affect 162Bug operation as described 
below. The default condition for the MVME162LX is with 
seven jumpers installed, between pins 1-2, 3-4, 5-6, 9-10, 11-
12, 13-14, and 15-16 (no jumper between pins 7-8).