USB
The Universal Serial Bus (USB) can be utilized for many functions on the development kit, including external media. The phyCORE-AM62Ax development kit provides two USB 2.0 Dual-Role Devices (DRD) subsystems via the three USB connectors (X43, X36, and X34). This guide will show you how to use the USB Host capabilities featured on the phyCORE-AM62Ax development kit. To learn more information about the phyCORE-AM62Ax USB interface, please see section 7.6 in the Hardware Manual.
The USB0 interface is brought out as a type-C connector (X34). The USB1 interface uses a USB HUB to split the bus to 3x locations.
Type |
Qty |
Header Location |
Speed |
Bus |
|---|---|---|---|---|
USB A Double Stacked |
2 |
X43 |
2.10 |
001 |
Mini PCIe |
1 |
X36 |
2.10 |
001 |
USB C |
1 |
X34 |
2.10 |
003 |
Requirements
Verifying USB Interface
With the development kit booted into Linux, verify that there are 2 USB devices.
Target (Linux)lsusb
Expected Outputroot@phyboard-lyra-am62axx-2:~# lsusb Bus 001 Device 002: ID 0424:2514 Bus 001 Device 001: ID 1d6b:0002 Linux 6.1.33-bsp-yocto-ampliphy-am62ax-pd23.1.0 xhci-hcd xHCI Host Controller
Insert a USB device into either x43 (Double stack USB-A port) or x34 (USB-C). This guide demonstrates the USB-A bottom port.
Expected Outputroot@phyboard-lyra-am62axx-2:~# [ 1103.995685] usb 1-1.2: new high-speed USB device number 3 using xhci-hcd [ 1104.101203] usb 1-1.2: New USB device found, idVendor=0781, idProduct=5591, bcdDevice= 1.00 [ 1104.109724] usb 1-1.2: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [ 1104.117146] usb 1-1.2: Product: SanDisk 3.2Gen1 [ 1104.121870] usb 1-1.2: Manufacturer: USB [ 1104.125981] usb 1-1.2: SerialNumber: 0401b360e7f994fa1045253b46381e7f4adf9e70e08383c7595d67e9a36da3592f6c0000000000000000000000c41f01009e5d18915581076e2cc63b [ 1104.197541] usb-storage 1-1.2:1.0: USB Mass Storage device detected [ 1104.204385] scsi host0: usb-storage 1-1.2:1.0 [ 1104.209411] usbcore: registered new interface driver usb-storage [ 1105.232338] scsi 0:0:0:0: Direct-Access USB SanDisk 3.2Gen1 1.00 PQ: 0 ANSI: 6 [ 1105.242820] sd 0:0:0:0: [sda] 30031872 512-byte logical blocks: (15.4 GB/14.3 GiB) [ 1105.251756] sd 0:0:0:0: [sda] Write Protect is off [ 1105.257122] sd 0:0:0:0: [sda] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA [ 1105.274728] sd 0:0:0:0: [sda] Attached SCSI removable disk
Verify that the USB was properly recongnized by development kit.
Target (Linux)lsusb
Expected Outputroot@phyboard-lyra-am62axx-2:~# lsusb Bus 001 Device 003: ID 0781:5591 USB SanDisk 3.2Gen1 Bus 001 Device 002: ID 0424:2514 Bus 001 Device 001: ID 1d6b:0002 Linux 6.1.33-bsp-yocto-ampliphy-am62ax-pd23.1.0 xhci-hcd xHCI Host Controller
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.
Target (Linux)lsusb -v -s 001:003
Note
“001” refers to bus 001 and “003” refers to the device number, both of these can be found in the lsusb command.
Bus 001 Device 003: ID 0781:5591 USB SanDisk 3.2Gen1
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.10
bDeviceClass 0
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 64
idVendor 0x0781
idProduct 0x5591
bcdDevice 1.00
iManufacturer 1 USB
iProduct 2 SanDisk 3.2Gen1
iSerial 3 0401b360e7f994fa1045253b46381e7f4adf9e70e08383c7595d67e9a36da3592f6c0000000000000000000000c41f01009e5d18915581076e2cc63b
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 0x0020
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 0
bmAttributes 0x80
(Bus Powered)
.. continues ..
The speed of the USB device can be determined with either the lsusb -v from above or by reading the device’s “speed”
Target (Linux)root@phyboard-lyra-am62axx-2:~# cat /sys/bus/usb/devices/1-1.2/speed 480 .. note:: USB2.0 has transmission speeds up to 480Mbit/s, also known as "full speed".
Mounting USB Stroage Devices
Verify that a device directory was established for the USB drive.
Run the following command to confirm the USB device name.
Target (Linux)ls /dev/sd*
Expected Outputroot@phyboard-lyra-am62axx-2:~# ls /dev/sd* /dev/sda
Remove the USB drive and re-insert it.
The output log that appears when connecting the USB device will indicate the devices name.
Expected Outputroot@phyboard-lyra-am62axx-2:~# [ 1103.995685] usb 1-1.2: new high-speed USB device number 3 using xhci-hcd [ 1104.101203] usb 1-1.2: New USB device found, idVendor=0781, idProduct=5591, bcdDevice= 1.00 [ 1104.109724] usb 1-1.2: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [ 1104.117146] usb 1-1.2: Product: SanDisk 3.2Gen1 [ 1104.121870] usb 1-1.2: Manufacturer: USB [ 1104.125981] usb 1-1.2: SerialNumber: 0401b360e7f994fa1045253b46381e7f4adf9e70e08383c7595d67e9a36da3592f6c0000000000000000000000c41f01009e5d18915581076e2cc63b [ 1104.197541] usb-storage 1-1.2:1.0: USB Mass Storage device detected [ 1104.204385] scsi host0: usb-storage 1-1.2:1.0 [ 1104.209411] usbcore: registered new interface driver usb-storage [ 1105.232338] scsi 0:0:0:0: Direct-Access USB SanDisk 3.2Gen1 1.00 PQ: 0 ANSI: 6 [ 1105.242820] sd 0:0:0:0: [sda] 30031872 512-byte logical blocks: (15.4 GB/14.3 GiB) [ 1105.251756] sd 0:0:0:0: [sda] Write Protect is off [ 1105.257122] sd 0:0:0:0: [sda] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA [ 1105.274728] sd 0:0:0:0: [sda] Attached SCSI removable disk .. note:: In this example the device name for the USB drive is "sda".
Make a directory for mounting the USB device.
Target (Linux)mkdir ~/usb_sda
Format file type.
Target (Linux)mkfs.vfat /dev/sda
Mount the USB device to the directory.
Target (Linux)mount /dev/sda ~/usb_sda/
See what media is on the USB drive.
Target (Linux)ls ~/usb_sda/
Write to the USB Host Device
Generate a random 10 MB file to test transferring data from the storage device.
Target (Linux)dd if=/dev/urandom of=test.file count=10 bs=1M
Expected Outputroot@phyboard-lyra-am62axx-2:~# 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, 0.156214 s, 67.1 MB/s
Copy the file to your storage device.
cp test.file ~/usb_sda/ && sync
Read from the USB Host Device
Copy the test file we previously created during the write process back to the host:
Target (Linux)cp ~/usb_sda/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:
Target (Linux)md5sum test.file readback-usb.file
Expected Outputroot@phyboard-lyra-am62axx-2:~# md5sum test.file readback-usb.file c6d65bf33f37847bad9f79ce241e59ed test.file c6d65bf33f37847bad9f79ce241e59ed 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
umount ~/usb_sda/
umount /dev/sda