Motorola MVME177 manual Memory Maps, Local Bus Memory Map, Normal Address Range

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Operating Instructions

Memory Maps

There are two possible perspectives or points of view for memory maps:

❏The mapping of all resources as viewed by local bus masters (local bus memory map)

❏The mapping of onboard resources as viewed by VMEbus Masters (VMEbus memory map)

Local Bus Memory Map

The local bus memory map is split into different address spaces by the transfer type (TT) signals. The local resources respond to the normal access and interrupt acknowledge codes.

There is some address translation capability in the VMEchip2. This allows multiple MVME177s on the same VMEbus with different virtual local bus maps as viewed by different VMEbus masters.

Normal Address Range

The memory map of devices that respond to the normal address range is shown in the following tables. The normal address range is defined by the Transfer Type (TT) signals on the local bus. On the MVME177, Transfer Types 0, 1, and 2 define the normal address range.

Table 3-1.Local Bus Memory Map, is the entire map from $00000000 to $FFFFFFFF. Many areas of the map are user-programmable, and suggested uses are shown in the table. The cache inhibit function is programmable in the MMUs. The onboard I/O space must be marked cache inhibit and serialized in its page table.

Table 3-2 on page 3-6further defines the map for the local I/O devices.

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