Hi, i'm using an X310. Is there any way to use the external GPIOs inside an RFNOC block ? regards. Christophe ALEXANDRE

Hi Christophe, Yes. The external GPIO is controlled by the radio block, so the custom RFNoC block would just have to generate the appropriate control packet to the radio and handle the ACK packet coming back. There will be some random amount of latency with that approach. If you need deterministic timing of the GPIO signals, you can supply a timestamp in the packet from your custom block, use timed commands from the host, or simply rewire the GPIO signals directly to the custom block. Regards, Michael On Mon, May 22, 2017 at 10:53 AM, Christophe ALEXANDRE via USRP-users < usrp-users@lists.ettus.com> wrote: > Hi, > > i'm using an X310. Is there any way to use > the external GPIOs inside an RFNOC block ? > > regards. > > Christophe ALEXANDRE > > > > _______________________________________________ > USRP-users mailing list > USRP-users@lists.ettus.com > http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com >

 Hi,

 i'm using an X310. Is there any way to use
 the external GPIOs inside an RFNOC block ?

   regards.

  Christophe ALEXANDRE



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thank you for your quick answer. do you have any figure about the random latency ? is there any documentation/example somewhere about : 1) generating the appropriate control packet 2) rewiring the GPIO signals directly to the custom block regards. Christophe ALEXANDRE Le 23/05/2017 à 03:06, Michael West a écrit : > Hi Christophe, > > Yes. The external GPIO is controlled by the radio block, so the > custom RFNoC block would just have to generate the appropriate control > packet to the radio and handle the ACK packet coming back. There will > be some random amount of latency with that approach. If you need > deterministic timing of the GPIO signals, you can supply a timestamp > in the packet from your custom block, use timed commands from the > host, or simply rewire the GPIO signals directly to the custom block. > > Regards, > Michael > > On Mon, May 22, 2017 at 10:53 AM, Christophe ALEXANDRE via USRP-users > <usrp-users@lists.ettus.com <mailto:usrp-users@lists.ettus.com>> wrote: > > Hi, > > i'm using an X310. Is there any way to use > the external GPIOs inside an RFNOC block ? > > regards. > > Christophe ALEXANDRE > > > > _______________________________________________ > USRP-users mailing list > USRP-users@lists.ettus.com <mailto:USRP-users@lists.ettus.com> > http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com > <http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com> > >

Hi Christophe, There is no real deterministic way of figuring out the latency since it takes time to send a packet from one block to another, but I would expect it to be <10us since the packet is small and the bus clock is 167 MHz. Unfortunately, there are no examples or documentation on how to do it yet. You will have to spend some time reading the code and figuring it out. The packet header format can be found here: https://github.com/EttusResearch/fpga/blob/maint/usrp3/chdr.txt Wiring the signals directly into the block is just basic FPGA design. Disconnect the fp_gpio lines from the radio block and connect them to your custom block. Perhaps an easier approach is to use the ATR feature of the GPIO. You can set up the GPIO to automatically switch values when it is idle, transmitting, receiving, or in full duplex (transmitting and receiving). You simply set desired values for each state. Regards, Michael On Mon, May 22, 2017 at 11:38 PM, Christophe ALEXANDRE < christophe.alexandre@cnam.fr> wrote: > thank you for your quick answer. > > do you have any figure about the random latency ? > > is there any documentation/example somewhere about : > > 1) generating the appropriate control packet > > 2) rewiring the GPIO signals directly to the custom block > > > regards. > > > Christophe ALEXANDRE > > > Le 23/05/2017 à 03:06, Michael West a écrit : > > Hi Christophe, > > Yes. The external GPIO is controlled by the radio block, so the custom > RFNoC block would just have to generate the appropriate control packet to > the radio and handle the ACK packet coming back. There will be some random > amount of latency with that approach. If you need deterministic timing of > the GPIO signals, you can supply a timestamp in the packet from your custom > block, use timed commands from the host, or simply rewire the GPIO signals > directly to the custom block. > > Regards, > Michael > > On Mon, May 22, 2017 at 10:53 AM, Christophe ALEXANDRE via USRP-users < > usrp-users@lists.ettus.com> wrote: > >> Hi, >> >> i'm using an X310. Is there any way to use >> the external GPIOs inside an RFNOC block ? >> >> regards. >> >> Christophe ALEXANDRE >> >> >> >> _______________________________________________ >> USRP-users mailing list >> USRP-users@lists.ettus.com >> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com >> > > >