Installing Exar Driver

The Atlys board includes a USB-UART bridge(Exar XR21V1410) which allows serial communication between FPGA and Host. The driver provided by Exar is outdated and does not work on newer Linux Kernel. Driver compatible with latest linux kernel can be found here.

Download driver

git clone https://github.com/shenki/exar-uart-driver.git

To install first remove old driver. Disconnect the USB-UART if it is already connected.

sudo rmmod cdc-acm
sudo rmmod vizzini
sudo modprobe -r usbserial

Install Drivers

cd exar-uart-driver
sudo modprobe usbserial
sudo insmod ./vizzini.ko

Connect the UART-USB bridge. The device should enumerated as dev/ttyUSBx.

To check whether the driver is successfully installed:

dmesg | grep -i tty

Ouput

......
[10118.569307] vizzini 3-2.3:1.0: ttyUSB0: XR21v14x usb uart device
.....