Xtium2-CL MX4 User's Manual
Installing Xtium2-CL MX4
•
31
Memory for this data is reserved in chunks of 64kB 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 1st 5MB for its own resources, which includes the 200 bytes
per frame buffer mentioned above.
Note 2
: Starting with Sapera LT 8.40, 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 1st 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.
•
The following calculation is an example of the amount of contiguous memory to reserve
beyond 5MB with 80,000 buffers of 2048x1024x8:
a) (80000 * 64 bytes)
b) (80000 * 48 bytes)
c) (80000 * (24 + (((2048*1024)/4kB) * 8))) = 323MB
d) Total = a (rounded up to nearest 64kB) + b (rounded up to nearest 64kB) + c (rounded
up to nearest 64kB).
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.
A Sapera application using the preferred
scatter gather buffers
could consume most of the
remaining system memory, with a large allocation of frame buffers. If using frame buffers allocated
as a
single contiguous memory block
, Windows will limit the allocation dependent on the installed
system memory. Use the Buffer menu of the Sapera Grab demo program to allocate host buffer
memory until an error message signals the limit allowed by the operating system used.
Contiguous Memory for Sapera Messaging
The current value for
Sapera messaging
determines the total amount of contiguous memory
reserved at boot time for messages allocation. This memory space stores arguments when a
Sapera function is called. Increase this value if you are using functions with large arguments, such
as arrays and experience any memory errors.
