USB

The Universal Serial Bus (USB) can be utilized for many functions on the phyBOARD-Lynx AM62Px, including external media. The phyBOARD-Lynx AM62Px provides multiple USB connectors, as detailed in USB Locations. This guide will show you how to use the USB Host capabilities featured on the phyBOARD-Lynx AM62Px. To learn more information about the phyCORE-AM62Px USB interface, please see section 7.6 in the Hardware Manual.

The USB0 interface is brought out as a USB-C connector (X8). The USB1 interface connects to a TUSB4041I USB 2.0 hub (U37), which splits the bus to the double stacked USB-A connector (X11) and the M.2 Key E connector (X20).

USB Locations
Type	Qty	Header Location	Controller	Speed
USB-A Double Stacked	2	X11	USB1, hub ports 1 (lower) and 2 (upper)	USB 2.0 High-Speed
M.2 Key E	1	X20	USB1, hub port 3	USB 2.0 High-Speed
USB-C	1	X8	USB0	USB 2.0 High-Speed

The USB-C port role is selected with jumper JP11:

USB-C Port Role (JP11)
JP11	Port Role
Open (default)	Dual-Role Port (DRP)
1+2	Downstream Facing Port (DFP, host)
2+3	Upstream Facing Port (UFP, device)

Requirements

USB Storage Device

Verifying USB Interface

Boot into Linux and Insert a USB Storage Device into one of the USB ports.
Upon insertion, kernel output should appear.

Verify the available USB devices.

In this example a USB storage device is inserted in both the lower and upper USB-A ports of X11.

phyboard-lynx-am62pxx-1:~# lsusb
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 002: ID 0451:8142 Texas Instruments, Inc. TUSB8041 4-Port Hub
Bus 001 Device 003: ID 0781:5591 SanDisk Corp. Ultra Flair
Bus 001 Device 004: ID 0781:5591 SanDisk Corp. Ultra Flair

To list more information about the USB device and buses on the development kit use the following command.

This command will output a good chunk of information. This guide will only show a snippet of the expected output for the USB drive that was just connected.
```
phyboard-lynx-am62pxx-1:~# lsusb -v
```
The speed of the USB device can be determined with either the lsusb -v from above or by reading the device’s “speed”

phyboard-lynx-am62pxx-1:~# lsusb -t
/:  Bus 001.Port 001: Dev 001, Class=root_hub, Driver=xhci-hcd/1p, 480M
    |__ Port 001: Dev 002, If 0, Class=Hub, Driver=hub/4p, 480M
        |__ Port 001: Dev 003, If 0, Class=Mass Storage, Driver=usb-storage, 480M
        |__ Port 002: Dev 004, If 0, Class=Mass Storage, Driver=usb-storage, 480M

Hub port 1 is the lower and hub port 2 the upper USB-A port of X11.

Note

USB2.0 has transmission speeds up to 480Mbit/s, also known as “high speed”.

Mounting USB Stroage Devices

Verify that a device directory was established for the USB drive.
1. Run the following command to confirm the USB device name.
```
phyboard-lynx-am62pxx-1:~# ls /dev/sd*
/dev/sda
```
1. Remove the USB drive and re-insert it.
2. The output log that appears when connecting the USB device will indicate the devices name.
Note

In this example the device name for the USB drive is “sda”.

Make a directory for mounting the USB device.

phyboard-lynx-am62pxx-1:~# mkdir -p /mnt/usb

Format file type.

phyboard-lynx-am62pxx-1:~# mkfs.vfat /dev/sda

Mount the USB device to the directory.

phyboard-lynx-am62pxx-1:~# mount /dev/sda /mnt/usb/

See what media is on the USB drive.

phyboard-lynx-am62pxx-1:~# ls /mnt/usb/

Write to the USB Host Device

Generate a random 10 MB file to test transferring data from the storage device.

phyboard-lynx-am62pxx-1:~# dd if=/dev/urandom of=test.file count=10 bs=1M
10+0 records in
10+0 records out
10485760 bytes (10 MB, 10 MiB) copied, 0.161874 s, 64.8 MB/s

Copy the file to your storage device.

phyboard-lynx-am62pxx-1:~# cp test.file /mnt/usb/ && sync

Read from the USB Host Device

Copy the test file we previously created during the write process back to the host:
```
phyboard-lynx-am62pxx-1:~# cp /mnt/usb/test.file readback-usb.file && sync
```

We can double check that the file was successfully copied to and from the USB device by checking the md5sum of the file:

phyboard-lynx-am62pxx-1:~# md5sum test.file readback-usb.file
d3aa3ee1db746d6f7fb66c9b42f4ea6b  test.file
d3aa3ee1db746d6f7fb66c9b42f4ea6b  readback-usb.file

Unmounting the Drive

Warning

Make sure the drive is unmounted prior to physically disconnecting the device. Failure to do so may result in loss of data and corruption of files

phyboard-lynx-am62pxx-1:~# umount /mnt/usb/