bf 537 SPORT

[EricP]

Has anyone tried  to interface a device using the SPORT on the Blackfin?  I am currently trying to do this with an ADC (AD7400A).  The ADC provides the clock source and a 1-bit data stream.  I have attached the vi I have been working on, I dont know if my problem is in the initialization of the SPORT or if has something to do with the buffer.  When I try to run this on the blackfin board I am getting a "data access misaligned access" exception status.  Any help would be greatly appreciated!

[Karunya_R]

Hi Eric.

Let me do some research on my end and see what I can find for you.

Thanks,

Karunya R

[majerus]

Eric I am trying to use the SPORT interface to read the data stream from an AD9874 eval board.  I am having the same issues that you are... "data access misaligned access".  I find that this is occurring for me when I configure the SPORT interface.  I am trying to set up my AD BF537 eval board to write out SPORT1 and read in on SPORT 0.  If I am successfull I will post a VI.

[Karunya_R]

Hi Eric,

I ran the program you gave me on a BF537. I did not have a device connected to my BlackFin board. When I just ran the code itself, I did not get a message about data misaligned access. I have attached a screen shot of it running.

Since you already have an open service request with me over the telephone on the same issue, it is easier to stick to one method of communication to resolve this issue.

Please let me know if you have any further questions. 

Thanks!

Karunya

[Karunya_R]

Hi Eric,

Let me also try to see if I can get hold of a AD board to test with the sport VI.

Thanks,

Karunya R

[majerus]

Have you made any progress on this problem?

[Karunya_R]

I could use some information to make this troubleshooting process a little easier. 

Do you get an error only with you have an AD9874 eval board connected to the BF board?

What BF board are you using?

[majerus]

I am using the bf-537 ezlite kit connected to a an-9874 eval board.  What I am having trouble with is reading the sport0 port into the blackfin.

[jmburns]

Hi Eric,

I haven't been able to test anything, but I can see a couple potential issues with your VI.  You need to make the Data Buffer In array a 10-element array of U16.  The Get Buffer VI just re-uses the memory area passed to it, so if you pass it an empty array, you won't get any data back.  The other thing to try is to place a BF Device Wait Buffer.vi between the Device Read.vi and the Get Buffer.vi so it has a chance to populate the full 10 elements before you read it.  Also, you don't want to initialize the SPORT port every time through your While Loop.  Try just initializing everything once outside the loop, then running the Enable - Read - Wait - Get - Disable (add this to the end) sequence inside the loop.

Hope that helps!

Regards,

Jason

[jmburns]

I realized my post might be a bit confusing, so here's a JPEG of what I mean.

Regards,

Jason