by support »
Hello,
The PMODs, as well as several other I/Os (push buttons etc.) go to pins that are routed to the PL (FPGA) part of the device. In out-of-the-box Xillinux, these pins are routed further to the PS (ARM processor's) GPIO pins.
Please refer to the xillydemo.ucf file for which physical pin goes to which GPIO.
This allows a very low-rate read/write access to these pins, using Linux' standard GPIO API. An example is shown on this page, incidentally demonstrating how to access PMOD B:
http://billauer.co.il/blog/2014/07/bash-gpio-xillinux/Note that Linux also supports a function API, which is significantly faster.
If the GPIO interface isn't fast enough, it's possible to modify the FPGA part, and route these pins to logic, which ends up interacting with Xillybus' IP core for capturing the data. In this case, common FPGA design techniques apply. For this case, please refer to section 5.4 of the Getting started with Xillinux for Zynq-7000 EPP guide (available at Xillybus' site's doc section) for avoiding possible problems.
Regards,
Eli
Hello,
The PMODs, as well as several other I/Os (push buttons etc.) go to pins that are routed to the PL (FPGA) part of the device. In out-of-the-box Xillinux, these pins are routed further to the PS (ARM processor's) GPIO pins.
Please refer to the xillydemo.ucf file for which physical pin goes to which GPIO.
This allows a very low-rate read/write access to these pins, using Linux' standard GPIO API. An example is shown on this page, incidentally demonstrating how to access PMOD B:
http://billauer.co.il/blog/2014/07/bash-gpio-xillinux/
Note that Linux also supports a function API, which is significantly faster.
If the GPIO interface isn't fast enough, it's possible to modify the FPGA part, and route these pins to logic, which ends up interacting with Xillybus' IP core for capturing the data. In this case, common FPGA design techniques apply. For this case, please refer to section 5.4 of the Getting started with Xillinux for Zynq-7000 EPP guide (available at Xillybus' site's doc section) for avoiding possible problems.
Regards,
Eli