Memory Maps

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VMEbus Interface and VMEchip2

The local bus to VMEbus interface and the VMEbus to local bus interface are provided by the VMEchip2. The VMEchip2 can also provide the VMEbus system controller functions. Refer to the VMEchip2 in Chapter 2 for detailed programming information.

Note that the ABORT switch logic in the VMEchip2 is not used. The GPI inputs to the VMEchip2 which are located at $FFF40088 bits 7-0 are not used. The ABORT switch interrupt is integrated into the

MC2 chip ASIC at location $FFF42043. The GPI inputs are integrated into the MC2 chip ASIC at location $FFF4202C bits 23-16.

Memory Maps

There are two points of view for memory maps: 1) the mapping of all resources as viewed by local bus masters (local bus memory map), and 2) the mapping of onboard resources as viewed by VMEbus masters (VMEbus memory map).

The memory and I/O maps which are described in the following tables are correct for all local bus masters. There is some address translation capability in the VMEchip2. This allows multiple MVME172 modules on the same VMEbus with different virtual local bus maps as viewed by different VMEbus masters.

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.

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 MVME172, Transfer Types 0, 1, and 2 define the normal address range. Table 1-2 is the entire

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Motorola MVME172 manual Memory Maps, VMEbus Interface and VMEchip2, Local Bus Memory Map, Normal Address Range