Dalsa X64 Xcelera-CL PX4, Руководство пользователя

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X64 Xcelera-CL PX4 User's Manual Installing X64 Xcelera-CL PX4
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Configuring Sapera
Viewing Installed Sapera Servers
The Sapera configuration program ( Start • Programs • DALSA • Sapera LT • Sapera Configuration )
allows the user to see all available Sapera servers for the installed Sapera-compatible boards. The System
entry represents the system server. It corresponds to the host machine (your computer) and is the only
server that should always be present.
Increasing Contiguous Memory for Sapera Resources
The Contiguous Memory section lets the user specify the total amount of contiguous memory (a block
of physical memory, occupying consecutive addresses) reserved for the resources needed for Sapera
buffers allocation and Sapera messaging . For both items, the Requested value dialog box shows the
driver default memory setting while the Allocated value displays the amount of contiguous memory that
has been allocated successfully. The default values will generally satisfy the needs of most applications.
The Sapera buffers value determines the total amount of contiguous memory reserved at boot time for
the allocation of dynamic resources used for host frame buffer management such as DMA descriptor
tables plus other kernel needs. Adjust this value higher if your application generates any out-of-memory
error while allocating host frame buffers. You can approximate the amount of contiguous memory
required as follows:
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Calculate the total amount of host memory used for frame buffers
[ number of frame buffers • number of pixels per line • number of lines • (2 - if buffer is 10 or 12
bits) ].
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Provide 1MB for every 256 MB of host frame buffer memory required.
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Add an additional 1 MB if the frame buffers have a short line length, say 1k or less
( the increased number of individual frame buffers requires more resources ).
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Add an additional 2 MB for various static and dynamic Sapera resources.
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Test for any memory error when allocating host buffers. Simply use the Buffer menu of the
Sapera Grab demo program (see
" Grab Demo Overview " on page 41 ) to allocate the number of
host buffers required for your acquisition source. Feel free to test the maximum limit of host
buffers possible on your host system – the Sapera Grab demo will not crash when the requested
number of host frame buffers cannot be allocated.
Host Computer Frame Buffer Memory Limitations
When planning a Sapera application and its host frame buffers used, plus other Sapera memory resources,
do not forget the Windows operating system memory needs. Window XP as an example, should always
have a minimum of 128 MB for itself.
A Sapera application using scatter gather buffers could consume most of the remaining system memory.
When using frame buffers allocated as a single contiguous memory block , typical limitations are one third