2 of 2 people found this helpful
I know that the GTR transceiver lanes for USB 3.0 have carefully controlled impedance requirements in order to achieve the 5000M speeds. On the UltraZed-EG, we first discovered that a special adapter is needed to achive the USB 3.0 speeds.
From this thread, I found the Xilinx recommended adapter:
Here is a link to this adapter which I have tested with the latest 2019.1 BSP along with a USB 3.0 mass storage device:
I have also found other similar adapters which I found also works with ZU+ kits for USB3.0 connectivity:
This forum thread mentions that there are others that developers have found success with, but I want to point out that I have not tested these myself to confirm compatibility with the Avnet kits:
Although I don’t fully understand the effects of the adapter myself, it appears in the Xilinx documentation and you can see that it is used on the ZCU102 board:
As for the IDT clock configuration, I don't have a scope in this location to test this and would need to check with the engineering lab to confirm the clock configuration you are reading with a fast enough oscilloscope. The IDT parts come pre-programmed with a fixed clock output configuration that should not change over time. In fact the devices can be customized to suit your end application needs for your own carrier design if needed:
According to the IO Carrier schematic, this is the clock configuration you will most likely want:
Thanks for your reply. In the meantime I've managed to get the board working as a USB device, connected to my PC as a host. At first I had the same problem that only USB 2 speed was detected, but it is now working with USB 3 super speed. I have set the jumpers so that the GTR0 clock is 52 MHz. I will try to get one of your recommended adapters for USB host connections.
I’m trying to get a USB 3 device working on the UltraZed I/O Carrier Card with an UltraZed-3EG SoM. The device is usually detected, but only as a USB 2 full-speed device. The USB drive I’m using for testing is definitely USB 3 and is detected as such on my PC. It also reports as super-speed capable on the UltraZed-3EG. I’ve tried the prebuild image from the Petalinux 2019.1 BSP, the image from the USB 3 performance test tutorial and images I’ve build myself. None of them run at the USB 3 speed. I’ve seen other reports of people having problems with their USB adapter cable. Mine is supposed to be USB 3 super-speed capable, but I might get a different one just in case.
I’m also confused with the setting of the GTR reference clocks. What clock input is used for USB and what frequency is expected for the prebuild images? I’m assuming it should be 52MHz on REFCLK0. I’ve scoped the REFCLK0 pin and found that the clock was only 26MHz and started testing different jumper settings. Can you confirm that this is the correct way to configure the clock chip?
- I2C Software Mode: JP1 removed, J1 and J2 placed at positions 2-3
- Hardware Config: JP1 placed (the IOCC user guide says not placed, but I think this is an error), and J1 and J2 placed at position 1-2 to select mode 3. Other modes can be selected by removing J1 and/or J2.
I’ve tried different configurations and found that they do not match table 13 in the IOCC user guide. Rather I’m observing the following frequencies on REFCLK0:
- Mode 0: 52 MHz
- Mode 1: 100 MHz
- Mode 2: 50 MHz
- Mode 3: 26 MHz
Since I believe the 52 MHz to be the expected frequency I switched to mode 0, but this also didn’t get me USB 3 speed. What exact clock/jumper settings are required for the prebuild images to work?