WWWBoard New Message: Message 648: Re: *** URGENT!! Problem with Cypress FX2 ISO transfers|
WWWBoard: Message 648
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Posted by Jeff Roberts on 05/22/02 at 8:52 PM|
Subject: Re: *** URGENT!! Problem with Cypress FX2 ISO transfers
In Reply to: *** URGENT!! Problem with Cypress FX2 ISO transfers posted by Rick on 05/22/02 at 6:52 PM:|
This is an end-user forum. Copy and paste your mesage here:
: I have purchased the Cypress FX2 development board am am writing my own windows application (Win2k) to transfer ISO data to and from the FX2.
: I have written code for the FX2 that takes data that is in EP2OUT and transfers it to the EP6IN buffer so that the host can read it back (Both EPs
: have a MaxPacketSize of 64). This transfer is done in the SOF interrupt service routine.
: So, i've set up my application so that the user can specifiy the number of packets, number of buffers, etc (as in the control panel application) to
: characterise the transfer. Therefore, the application takes the parameter values and writes data to the FX2 through pipe 0 (EP2OUT). The user then
: prompts the application to read the data back through pipe 1 (EP6IN). However, when i attempt to read back the data that was written to the FX2, i
: only get back a portion of the data.
: Having performed many transfers with different parameter values, it seems that i can never read back more than 4 packets of data.
: The following results were recorded.
: # Pkts PktSize #Buffers Frms/Buffer #PktsReadBack Success
: 1 16 1 1 1 yes
: 2 16 1 1 1 no
: 2 16 2 1 2 yes
: 4 16 2 2 4 yes
: 4 16 2 1 3 no
: 4 16 1 2 4 yes
: 6 16 3 2 4 no
: 6 16 2 3 4 no etc.......
: An interesting observation was that when there is only 1 buffer, the application seems to read back every second packet that was sent. I have a
: feeling that there is something wrong with the way the buffer count is being used in the transfers.
: I cannot find out where the problem lies. I am careful to reset the pipe before every ISO transfer. I have analysed the code for the control panel
: application but i cannot find where i could be going wrong. I have also tried using both the control panel and my own application (ie. writing to the
: FX2 with one app, and then reading from the FX2 with the other app, and vice versa) to try and pinpoint the location of the problem. It seems that
: my application is not writing the whole burst of data. However, i know through these tests that my read isn't working either.
: Could anyone provide me with some help on this problem???