SBS Technologies 466-1, Hardware Manual

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Model 466-1 Adapter
6 Adapter Functions
1.2 VMEbus Address Modifier Types Supported
For SBus random access to the VMEbus, any address modifier, except
VME64, can be supported via the VMEbus adapter card Address Modifier
Register. If the Address Modifier Register is not used, then the default
values are:
r
2D for VMEbus I/O.
r
3D for A24 access.
r
0D for A32 access.
For VMEbus access to Dual Port RAM, all A24 and A32 address
modifiers are accepted.
In 32-bit mode, Dual Port RAM responds to address modifiers 09, 0A,
0D, and 0E.
In 24-bit mode, Dual Port RAM responds to address modifiers 39, 3A,
3D, and 3E.
For VMEbus access to adapter control and status register I/O space:
r
2D for Short Supervisory access.
r
29 for Short Non-Privileged access.
1.3 Bus-To-Bus Mapping
The Model 466-1 adapter works by mapping a portion of memory address
space in the SPARCstation into memory address space on the VMEbus. The
SBus adapter card maps sections of its SBus slot to memory or I/O accesses on
the VMEbus. The VMEbus address spaces appear to a SBus processor as
though they were present in the SBus chassis and behave as if they were local
memory.