We have been able to get more or less all functions of the ATSAMA5D31 working except the USB client port. (Which is somewhat irritating as first programming over JTAG is soo much slower…)
The normal scenario is that the computer says the connected USB unit is not recognized. Rarely we get to the next step and it is shown as a COM-port. But never been able to use SAM-BA to program it.
What we tried so far is:
- 1. Replace the 12 MHz crystal with 4-5 different alternatives from other suppliers.
- 2. Modify the load capacitors on the crystal with different values. (Manually measured the frequency to be spot-on 12 Mhz.)
- 3. Soldered a USB cable directly to vias very close to the processor. (Signal wires on PCB were cut to avoid stubs.)
- 4. Added caps to power nets VDDUTMIC and VDDUTMII.
Open for any tips or ideas. Helpful just to know if anyone are successfully using the USB port on ATSAMA5D31.