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Installing Xtium2-CXP PX8
Xtium2-CXP PX8 User's Manual
Configuring Sapera
The Sapera Configuration program (on the Start menu, select Teledyne 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 CorMem driver default memory setting while the Allocated value displays the
amount of contiguous memory allocated successfully. The default values will generally satisfy the
needs of most applications.
The Buffer Allocation (Legacy) and Buffer Allocation (64-bit) value determines the total amount of
contiguous memory reserved at boot time for the allocation of dynamic resources used for frame
buffer management such as scatter-gather list, DMA descriptor tables plus other kernel needs. We
recommend using the 64-bit choice for the Xtium2-CXP PX8 in order to reserve this memory
anywhere in PC memory and not just limited to the 1
st
4 GB of physical memory as would be the
case using the Legacy one.
Adjust this value higher if your application generates any out-of-memory error while allocating host
frame buffers or when connecting the buffers via a transfer object. You can approximate the worst-
case scenario amount of contiguous memory required as follows:
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Calculate the total amount of host memory used for one frame buffer
[number of pixels per line * number of lines * (2 - if buffer is 10/12/14 or 16 bits)].
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Provide 200 bytes per frame buffer for Sapera buffer resources.
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Provide 64 bytes per frame buffer for DMA metadata. Memory for this data is reserved in
chunks of 64 kB blocks.
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Provide 48 bytes per frame buffer for buffer management. Memory for this data is reserved in
chunks of 64 kB blocks.
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For each frame buffer DMA table, allocate 24 bytes + 8 bytes for each 4 kB of buffer. For
example, for a 120x50x8 image: 120x50 = 6000 = 1.46 4kB blocks -> roundup to 2 blocks of
4kB. Therefore 24 bytes + (2 * 8 bytes) = 40 bytes for DMA tables per frame buffer. Memory
for this data is reserved in chunks of 64 kB blocks. If vertical flipping is enabled, one must add
16 bytes per line per buffer. For example, for an image 4080x3072 image: 16 bytes * 3072 =
49152 bytes.
Note 1: Sapera LT reserves the 1
st
5 MB for its own resources, which includes the
200 bytes per frame buffer mentioned above.
Note 2: Contiguous memory can be allocated anywhere in PC memory using the
Buffer Allocation (64-bit) entry in Sapera Configuration Tool. The driver will use this
memory 1
st
for frame buffer DMA tables.
Test for any memory error when allocating host buffers. Simply use the Buffer menu of the Sapera
Grab demo program (see Grab Demo Overview) 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 is
not allocated.
