VXI Resource Manager

The VXIbus device protocols define how modules are granted non-conflicting portions of the VMEbus address space. Several devices may exist on a single module, and a single device may consist of multiple modules. 256 devices may exist in any one VXIbus system. A VXIbus system configuration space is defined in the upper 16K bytes of the A16 address space. Each device is granted a total of 64 bytes in this space. Devices requiring additional address space have their address requirements readable in a defined register in the A16 address space. The Resource Manager reads this value shortly after power-on and then assigns the requested memory space by writing the module's new VMEbus address into the device offset register. The Resource Manager may assign space in the A24 and A32 address spaces by this means.

The Resource Managers are interlinked so that signals may be shared between all VXI crates (for example the trigger validation).

The Eurogam Resource Manager contains a standard VME processor module (Motorola MVME147) which provides the communications path between the VXI modules and the control software.