Motorola MVME197LE - Manual (Page 28)

Hardware Preparation and Installation
2-8 User’s Manual
2
are provided in the MVME197LE, MVME197DP, and MVME197SP Single
Board Computers Programmer’s Reference Guide). Some cable(s) are not
provided with the MVME712X module and therefore, are made or
provided by the user. (Motorola recommends using shielded cables for all
connections to peripherals to minimize radiation). Connect the
peripherals to the cable(s). Detailed information on the EIA-232-D signals
supported is found in Appendix A.
g. Install any other required VMEmodules in the system.
h. Replace the chassis cover.
i. Connect the power cable to the ac power source and turn the equipment
power ON .
System Considerations
The MVME197LE needs to draw power from both connectors P1 and P2 of the
VMEbus backplane. Connector P2 is also used for the upper 16 bits of data for
32-bit transfers, and for the upper 8 address lines for the extended addressing
mode. The MVME197LE may not operate properly without its main board
connected to connectors P1 and P2 of the VMEbus backplane.
Whether the MVME197LE operates as a VMEbus master or as a VMEbus slave,
it is configured for 32 bits of address and for 32 bits of data (A32/D32).
However, it handles A16 or A24 devices in certain address ranges. D8 and/or
D16 devices in the system must be handled by software. Refer to the memory
maps in the MVME197LE, MVME197DP, and MVME197SP Single Board
Computers Programmer’s Reference Guide.
The MVME197LE contains shared onboard DRAM whose base address is
software-selectable. Both the onboard processor and off-board VMEbus
devices see this local DRAM at base physical address $00000000, as
programmed by the MVME197Bug firmware. This may be changed, by
software, to any other base address. Refer to the MVME197LE, MVME197DP,
and MVME197SP Single Board Computers Programmer’s Reference Guide for
details.
If the MVME197LE tries to access off-board resources in a non-existent
location, and is not the system controller, and if the system does not have a
global bus timeout, the MVME197LE waits forever for the VMEbus cycle to
complete. This would cause the system to hang up. There is only one situation
in which the system might lack this global bus timeout: when the
MVME197LE is not the system controller and there is no global bus timeout
elsewhere in the system.