Peritek
6-2
Troubleshooting
6.2 Selecting an Address Range for your Board
Note
It is necessary to determine the correct address ranges of your CPU
before
you attempt to run the Peritek software. If you are unable to do so, even
after reading this section, please contact Peritek for assistance.
Most CPU boards used on the VMEbus have a 32-bit physical address
space, even if the CPU chip itself only puts 24 bits (i.e. 68000 or 68010).
Normally a bus controller chip (such as the VIC068 or SCV64), located on
the CPU board, converts the CPU chip's physical addresses to VMEbus
addresses. Certain blocks of VMEbus address space are assigned to A16,
A24, and A32 VMEbus address types. Unfortunately, since the VMEbus
specification does not dictate a memory map for the address types, each
manufacturer's board has its own assignments.
Clearly, knowledge of the details of the processor board memory map are
important: you need to know the map in order to test out the board.
Normally, the CPU board's boot PROM will set up the A16, A24, and A32
address space assignments in its local bus controller. If a controller chip
isn't used, then the map will be hardwired into the CPU board design.
For A16 space, the high 16 bits of the CPU chip's address space is
determined by the memory map (and thus the bus controller). What this
means is that although the CSR block in the graphics board itself only sees
the VMEbus address bits A1-A15, you actually use a 32-bit address in the
CPU chip to address the board. The high 16 bits of the address is
predetermined by the bus controller as corresponding to an A16 segment.
Given the broad range of computers which support the VMEbus, it is
impossible to cover installation on all of them. However, we have
provided in the following table a representative sampling. The table below
summarizes the relevant A16, A24, and A32 spaces. All boards support
A24 spaces too, and the graphics board can use it. This would only be
necessary if your CPU doesn't support A16/D32 accesses. D32 accesses
give the best data transfer performance. If you encounter difficulty, please
do not hesitate to contact the factory for assistance.
Summary of Contents for VCD-V
Page 2: ...Peritek ...
Page 3: ...Peritek ...
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Page 42: ...Peritek Installing Your Peritek Graphics Board 2 11 Figure 2 3 Jumper Locations for the VCD V ...
Page 94: ...Peritek Theory of Operation 4 15 Figure 4 1 VCD V Block Diagram ...
Page 95: ...Peritek 4 16 Theory of Operation Figure 4 2 VCU V Block Diagram ...
Page 96: ...Peritek Theory of Operation 4 17 Figure 4 3 VCT V Block Diagram ...
