Hello, the last day I am banging my head against the problem how the data is structured for the USB transfer between the FX2 and the PC. Datasheet, FX2 reference and the web didn't givve me the right clue. What I understand: - the FPGA pumps interleaved samples into the FX2 fifo via GPIF. E.g. http://www.nd.edu/~jnl/sdr/docs/tutorials/4.html talks about a sequence I0 Q0 I1 Q1 I2 Q2 I3 Q3 I0 Q0 I1 Q1, etc. - these samples are somehow grouped into 512 byte blocks and sent over USB - the PC receives these blocks and must somehow know where a data group starts
I can only think that always 512 byte blocks are transferred. With a full number of data groups fitting into the block, the block would always start with I0. But what happens if the PC gets out of sync, by not reading a full block with some strange event? Then the next 512 byte blocks read would always start somewhere in the datagroup. Any way to resync? Are short packets and the PKTEND signal used? Thanks for any hints -- Uwe Bonnes [EMAIL PROTECTED] Institut fuer Kernphysik Schlossgartenstrasse 9 64289 Darmstadt --------- Tel. 06151 162516 -------- Fax. 06151 164321 ---------- _______________________________________________ Discuss-gnuradio mailing list [email protected] http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
