FIFO in pci 6534

[Vishal]

Hye friends, here some questions arised related to the DMA operation and FIFO of pci 6534.
6534 has 32 byte FIFO right?
1.) Now if i am using only one group at a time, it uses the whole FIFO right?
2.)if i am using two groups parallely,how FIFO will be managed?
3.) if i am using two groups in strobed mode and at the same time if i am doing unstrobed operation also, how FIFO will be managed?
4.)At this time how the onboard memory will be used with unstrobed operation?because we have two onboard memory for two groups. And here i am using two groups plus unstrobed operation. Consider that i am using port 0 & port 2 in pattern input mode & port 1 in unstrobed input mode.
So how 6534 manage FIFO size in different combinations.Please help me. Thanks in
advance.

[JustinBritten]

Vishal,

The FIFO is 32MB, not 32 bytes. Additionally, this is 32MB per group (32MB for input, 32MB for output, totalling 64MB on the board). You cannot use the entire 64MB for input if you are not doing any output. Each group only has access to 32MB.

This means that if you have a pattern I/O operation then input will have access to 32MB and output to the other 32MB. No matter what type of input operation you are programming, you will only have access to 32MB. If you have two pattern input operations then the buffer allocated for each must be less than 32MB.

For more information on this subject, please see the following Knowledge Base article available on our website.

How Many Samples of Data Can I Store in the Onboard Memory of the NI 6534?
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ttp://digital.ni.com/public.nsf/websearch/DA52DD262285520686256A470065E589?OpenDocument

Regards,
Justin Britten

Applications Engineer
National Instruments