Re: [Discuss-gnuradio] usrp intraction with gnuradio

[Jeremy Quirke]

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: address@hidden
> [mailto:address@hidden On Behalf
> Of sh.sharma
> Sent: Friday, 29 April 2011 4:19 PM
> To: address@hidden
> 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
> >> > address@hidden
> >> > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
> >> >
> >> >
> >>
> >
> >
> >
> > _______________________________________________
> > Discuss-gnuradio mailing list
> > address@hidden
> > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
> >
> >
> 
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