Technical data

Bringing up the Board

http://www.mcg.mot.com/literature 2-9

However, if the MVME172LX loses power but the controller

does not, and the tape happens to be at load point, the

necessary command sequences (attach and rewind) cannot be

given to the controller and the autoboot will not succeed.

ROMboot

As shipped from the factory, 172Bug occupies an EPROM installed in

socket XU2. This leaves one socket (XU1) and the Flash memory available

for your use.

Note You may wish to contact your Motorola sales office for

assistance in using these resources.

The ROMboot function is configured/enabled via the ENV command

(refer to Chapter 3) and is executed at power-up (optionally also at reset).

You can also execute the ROMboot function via the RB command,

assuming there is valid code in the memory devices (or optionally

elsewhere on the board or VMEbus) to support it. If ROMboot code is

installed, a user-written routine is given control (if the routine meets the

format requirements).

One use of ROMboot might be resetting the SYSFAIL∗ line on an

unintelligent controller module. The NORB command disables the

function.

For a user’s ROMboot module to gain control through the ROMboot

linkage, four conditions must exist:

❏ Power has just been applied (but the ENV command can change this

to also respond to any reset).

❏ Your routine is located within the MVME172LX Flash/PROM

memory map (but the ENV command can change this to any other

portion of the onboard memory, or even offboard VMEbus

memory).

❏ The ASCII string "BOOT" is found in the specified memory range.