System Considerations - Motorola MVME2400 Series Installation And Use Manual

Hardware Preparation and Installation
1

System Considerations

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The MVME240x draws power from the VMEbus backplane connectors P1
and P2. P2 is also used for the upper 16 bits of data in 32-bit transfers, and
for the upper eight address lines in extended addressing mode. The
MVME240x may not function properly without its main board connected
to VMEbus backplane connectors P1 and P2.
Whether the MVME240x operates as a VMEbus master or as a VMEbus
slave, it is configured for 32 bits of address and 32 bits of data (A32/D32).
However, it handles A16 or A24 devices in the address ranges indicated in
Chapter 4, Programming
must be handled by the PowerPC processor software. Refer to the memory
maps in Chapter 4, Programming
The MVME240x 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 PPCBug firmware. This may be changed via software
to any other base address. Refer to the MVME240x Programmer's
Reference Guide for more information.
If the MVME240x tries to access off-board resources in a nonexistent
location and is not system controller, and if the system does not have a
global bus timeout, the MVME240x waits forever for the VMEbus cycle
to complete. This will cause the system to lock up. There is only one
situation in which the system might lack this global bus timeout: when the
MVME240x is not the system controller and there is no global bus timeout
elsewhere in the system.
Multiple MVME240x boards may be installed in a single VME chassis.
Each must have a unique Universe address, selected by setting jumpers on
its J17 header, as described in
general, hardware multiprocessor features are supported.
Other MPUs on the VMEbus can interrupt, disable, communicate with,
and determine the operational status of the processor(s). One register of the
Universe set includes four bits that function as location monitors to allow
Details. D8 and/or D16 devices in the system
Details.
MVME2400 Base Board
Computer Group Literature Center Web Site
Preparation. In