There is no "code" that transfers data to/from the FPGA to the Cypress.
It is a purely a hardware transaction. To be strictly correct, the USRP makes use of the programmable GPIF interface of the Cypress EZUSB, the programming of the GPIF is done in the *gpif*.c files. See chapter 10 of the EZUSB literature. The data is copied in/from the EZUSB FIFOs which are written/read by USB transfers. See usrp_main.c for the loop that sets up read/write transfers. Regards, Jeremy > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf > Of sh.sharma > Sent: Friday, 29 April 2011 4:19 PM > To: [email protected] > Subject: Re: [Discuss-gnuradio] usrp intraction with gnuradio > > > Hi Nick, > Thanks for your geniune guide and it was very helpful from my side in > clearing the doubts which i had in my mind regarding the usrp block. > > And i apologize again for the confusion created by my other part of > the > post. > What i wanted to know is that , when data got transfered from FPGA to > the > Cyprex chip , my doubt is that , is there any involvement of the c++ > code in > transferring data from FPGA to Cyprex and vice versa.And if c++ code is > not > involved in the transaction then , .rbf file should have automatically > doing > that... I just wanted to know what part of the C++ code is used in the > data > transfer from fpga to cyprex chip. > > and just want to confirm that data form cyprex is recived by libusb > function > "usb_bulk_read" called in "read" function of "fusb_ephandle_generic" > class > in a buff string & send to the usrp_source... > > i apologize if my question is still not clear enough. > thanks > > > > Nick Foster-4 wrote: > > > > On Wed, 2011-04-27 at 23:19 -0700, sh.sharma wrote: > >> sorry for insufficient information for my previous post i highly > >> apologize > >> for that ... > >> > >> what i wanted to ask was that... > >> i am trying to understand gnuradio & i want to know which part of > >> gnuradio > >> initially receive data from usrp... > >> I means , where in the gnuradio code does the work of actual reading > the > >> fifo in the Cyprex Fx2 USB with the help > >> of the libusb and the libpcap library... > >> > >> In trying to understand the my problem, i start tracing > usrp_rx_cfile... > >> some of the work i have done & track a function named usb_bulk_read > >> called > >> in read function of fusb_ephandle_gfeneric class... > >> i think it reads data from usb(cyprex) part of USRP... > >> but i want to know that which part of the code in gnuradio/USRP > block > >> code > >> put the data in that cyprex part , and if this is automatically done > by > >> the > >> hardware board, then where is the code that is involve in this > >> transaction.. > > > > If you're asking about the older gr-usrp drivers, then: > > > > gnuradio/usrp contains the driver that talks USB to the USRP, and the > > firmware and FPGA code that run on the USRP itself. > > > > gnuradio/gr-usrp contains the bridge that gets USRP data from the > driver > > into Gnuradio. > > > > The USRP has a Cypress FX2 USB controller which uses the GPIF > interface > > to talk to the Cyclone FPGA and read data from it. The firmware to > > control the FX2 is in the gnuradio/usrp/firmware directory. The > Cyclone > > FPGA code is in gnuradio/usrp/fpga. The firmware on the FX2 isn't > smart > > enough to do anything but SPI, I2C transfers, etc. so all the control > > and tuning logic is in the host side driver, in gnuradio/usrp/host. > > > >> > >> 1. my current objective is to know about the complete data path of > >> USRP--->rx_cfile.... > >> i want to get the part from that the C++ takes control... > >> > >> 2. Or is it some of the important part id done other than C++ (means > >> verilog, matlab etc..) or these languages work only like drivers of > >> USRP... > > > > If you describe what you're trying to do, we might be able to give > you > > more specific suggestions. > > > > --n > > > >> > >> Thanks for any help... > >> & i highly apologize for any incorrect or illogical question... > >> > >> > >> > >> Nick Foster-4 wrote: > >> > > >> > On Wed, 2011-04-27 at 06:33 -0700, sh.sharma wrote: > >> >> How usrp intract with gnuradio... > >> >> data is sent by usrp to gnuradio > >> >> > >> >> or > >> >> > >> >> how gnuradio usrp block intract withgnuradio-core > >> > > >> > If you ask good, detailed questions about specific Gnuradio > topics, you > >> > will get good, detailed answers about specific Gnuradio topics. > >> > Otherwise, you'll get replies like this. > >> > > >> > --n > >> > > >> > > >> > _______________________________________________ > >> > Discuss-gnuradio mailing list > >> > [email protected] > >> > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > >> > > >> > > >> > > > > > > > > _______________________________________________ > > Discuss-gnuradio mailing list > > [email protected] > > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > > > > > -- > View this message in context: http://old.nabble.com/urrp-intraction- > with-gnuradio-tp31487487p31502882.html > Sent from the GnuRadio mailing list archive at Nabble.com. > > > _______________________________________________ > Discuss-gnuradio mailing list > [email protected] > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio _______________________________________________ Discuss-gnuradio mailing list [email protected] https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
