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[Previous] [Up] [Top] [Contents] [Back]3.7 VMEbus Interface
A 4-kByte section of the local SRAM is shared on the VMEbus. This memory can be read from or written to by the local processor as well as by a VMEbus master. The shared memory supports read-modify-write cycles from the local processor as well as from the VMEbus master.
The base address of the shared memory on the VMEbus depends on the Module ID installed. The shared memory is accessible in the standard (A24) address space, and takes 4 kBytes in the memory map starting at $C00000 + (Module ID x $1000). The shared memory takes 4 kBytes in the A24 memory map, and modules with successive module IDs will take consecutive 4 kByte memory blocks.
The on-board shared SRAM is used for communication with VMEbus masters, and a part of the shared SRAM is assigned to a mailbox. By writing to this mailbox a VMEbus master is able to interrupt or reset the local processor.
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