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OpenCores.Org USB1.1 Function Controller Success Story
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OpenCores.Org USB1.1 Function Controller Success Story
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As part of the undergraduate program in Computer Engineering at the
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As part of the undergraduate program in Computer Engineering at the
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University of Waterloo, all students must participate in a fourth year
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University of Waterloo, all students must participate in a fourth year
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design project. Our team created a PC Oscilloscope, since we had
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design project. Our team created a PC Oscilloscope, since we had
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frequently encountered problems with a lack of access to oscilloscopes
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frequently encountered problems with a lack of access to oscilloscopes
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when working on our own personal projects. Real oscilloscopes are
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when working on our own personal projects. Real oscilloscopes are
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expensive, and definitely outside our student budgets. Our concept was
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expensive, and definitely outside our student budgets. Our concept was
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to create a cheap, full featured oscilloscope by harnessing a PC’s
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to create a cheap, full featured oscilloscope by harnessing a PC’s
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computing power and display ability.
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computing power and display ability.
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When designing the oscilloscope, we quickly concluded that we needed a
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When designing the oscilloscope, we quickly concluded that we needed a
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relatively high bandwidth, common and affordable connection between a
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relatively high bandwidth, common and affordable connection between a
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PC and our device. USB was the natural choice. Our school had provided
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PC and our device. USB was the natural choice. Our school had provided
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us with an Altera Excalibur FPGA development kit, so we began by
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us with an Altera Excalibur FPGA development kit, so we began by
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searching for USB Core IP. After a few promising leads, none of the
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searching for USB Core IP. After a few promising leads, none of the
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companies were willing to donate a USB function controller to our
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companies were willing to donate a USB function controller to our
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project.
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project.
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At this point, Evan Jones remembered hearing about OpenCores, and
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At this point, Evan Jones remembered hearing about OpenCores, and
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immediately discovered the USB1.1 function controller. We began by
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immediately discovered the USB1.1 function controller. We began by
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reading the little documentation that was available. Since the author
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reading the little documentation that was available. Since the author
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of the component used a Phillips USB tranceiver and Philips does not
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of the component used a Phillips USB tranceiver and Philips does not
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provide samples of that particular part, we ordered samples of a
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provide samples of that particular part, we ordered samples of a
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nearly pin USB tranceiver from Fairchild Semiconductor. Meanwhile, we
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nearly pin USB tranceiver from Fairchild Semiconductor. Meanwhile, we
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compiled the component with the Altera Quartus tools.
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compiled the component with the Altera Quartus tools.
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Once the trancievers arrived, we soldered up a quick circuit to connect
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Once the trancievers arrived, we soldered up a quick circuit to connect
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the USB cable to our prototype board. The very first time we connected
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the USB cable to our prototype board. The very first time we connected
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the device to our PC, the PC crashed. We assumed that this was a good
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the device to our PC, the PC crashed. We assumed that this was a good
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sign, as at least the PC was seeing the USB device. After some more
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sign, as at least the PC was seeing the USB device. After some more
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debugging using another computer running Linux, we determined that
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debugging using another computer running Linux, we determined that
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while the device and the PC were communicating, something was going
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while the device and the PC were communicating, something was going
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wrong. The PC was reporting that the device was sending “babble”.
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wrong. The PC was reporting that the device was sending “babble”.
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We spent the next few days debugging. First we resoldered our USB
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We spent the next few days debugging. First we resoldered our USB
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interface circuit to reduce noise. We manually decoded the signals on
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interface circuit to reduce noise. We manually decoded the signals on
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the USB bus using an oscilloscope. We were stumped. It looked like the
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the USB bus using an oscilloscope. We were stumped. It looked like the
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beginning of the USB enumeration was working correctly, but it would
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beginning of the USB enumeration was working correctly, but it would
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still fail and reset the bus.
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still fail and reset the bus.
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We took a break and returned to it in a few days and redid absolutely
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We took a break and returned to it in a few days and redid absolutely
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everything from scratch. This time the PC detected an unknown USB
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everything from scratch. This time the PC detected an unknown USB
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device. It turns out that our problem was that we set an incorrect
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device. It turns out that our problem was that we set an incorrect
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setting in the VHDL header for our particular FPGA. With the default
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setting in the VHDL header for our particular FPGA. With the default
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settings and a recompile, the device worked.
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settings and a recompile, the device worked.
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It took us a few more weeks until we worked out our software device
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It took us a few more weeks until we worked out our software device
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driver and the remainder of the device logic, but that was all
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driver and the remainder of the device logic, but that was all
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relatively straightforward. The OpenCores USB function controller
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relatively straightforward. The OpenCores USB function controller
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worked as advertised. If we were to do the project again, we would
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worked as advertised. If we were to do the project again, we would
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easily be able to get it up and running in a few hours.
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easily be able to get it up and running in a few hours.
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Evan Jones http://www.eng.uwaterloo.ca/~ejones/
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Evan Jones http://www.eng.uwaterloo.ca/~ejones/
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Mauro Loconsolo 4ydp_waterloo@rogers.com
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Mauro Loconsolo 4ydp_waterloo@rogers.com
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Evan Robinson e2robins@uwaterloo.ca
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Evan Robinson e2robins@uwaterloo.ca
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Sahand Sojoodi sahands@hotmail.com
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Sahand Sojoodi sahands@hotmail.com
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