UM0851 Datasheet, PDF (67/245 Pages) STMicroelectronics – SPEAr is a family of highly customizable ARM-based embedded

UM0851
Communication device drivers
Table 20.
BlkSize
(KB)
320
400
USB Host device performance results (continued)
Data Size
(KB)
BulkOUT time
(s)
BulkOUT
throughput
(Mbps)
BulkIN time
(s)
32000
0.959063
273.3334515 0.933094
40000
1.160719
282.3077765 1.160719
BulkIN
throughput
(Mbps)
280.9406126
282.3077765
Figure 14. USB Host performance at buffer length=4096
4.3.5
Kernel configuration options
To ensure proper USB support for your devices, you need to enable some of the options in
the kernel.
The following table shows the configuration options.
Table 21. USB host configurations
Configuration option
Comment
CONFIG_USB_SUPPORT
This option adds core support for USB bus.
CONFIG_ USB
Enable this option if your system has the host side bus and you
want to use USB devices and also see your USB devices in
/proc/bus/usb. This is recommended.
CONFIG_ USB_DEVICES
If you enable this option, you will get a file
/proc/bus/usb/devices which lists the devices currently
connected to your USB bus or buses, and a file named
"/proc/bus/usb/xxx/yyy" for every connected device, where xxx
is the bus number and yyy the device number.
CONFIG_ USB_EHCI_HCD
Since the USB Host controller supports USB2.0, enable this
option to configure the Host controller driver. EHCI is standard
for USB 2.0 high-speed host control hardware.
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