OK, lots of questions. We'll do our best to answer them here, but it might be easier to fill in the details via phone call.
The board can DMA to host memory buffers with top to bottom or bottom to top. The direction must be set up before acquisition starts, however it does not take that much time to change the direction, but you do have to stop acquisition before you can make changes.
Currently from our high level API we support the following modes:
1. All frames top to bottom
2. Even frames top to bottom, odd frame bottom to top.
3. Odd frames top to bottom, even frame bottom to top.
4. All frame bottom to top.
This should be enough for most XY stages, but if you have more complicated needs, the direction can be customized for each frame in a series.
Our frame grabber do support capture of variable size frames. The size of the frame is controlled by and external trigger type signal. Basically the board starts a frame with the signal asserts and ends when the signal de-asserts. This technique is supported by our high level APIs, so no special programming is needed. All you should need is a camera configuration file that puts the board in this mode.
You can combine the frame inversion with the bottom to top DMA direction.
We do have some hardware methods to crop buffers, however, we probably need to get some more details from you in order to know if we really can support your cropping scheme or not.
We hope this information is helpful, please let us know if you have further questions.
We do try to answer questions here as quickly as possible, but support emails take priority. If you are in a hurry to get an answer, please email support @ bitflow . com.