xr21b1411 Exar Corporation, xr21b1411 Datasheet - Page 25

• Manufacturer Part Number: xr21b1411
• Description: Enhanced 1-ch Full-speed Usb Uart
• Manufacturer: Exar Corporation

REV. 1.1.0
USB_ATTRIBUTES[4:0]: Reserved
USB_ATTRIBUTES[5]: REMOTE_WAKEUP
USB_ATTRIBUTES[6]: SELF_POWERED
Bit[6] of the bmAttributes field of the device descriptor. If OTP_VALID.USB is set to 1, then this bit is set to
indicate that the device is self powered. If the device also requires bus power to be reserved, then that power
requirement is given by the USB_MAXPOWER field.
USB_ATTRIBUTES[7]: Reserved
This bit is reserved and should remain ’0’
USB_MAXPOWER[7:0]: Value
The bMaxPower field of the device descriptor. It is expressed in units of 2 mA. If OTP_VALID.USB is set to 1,
then this indicate the power requirement of the device.
ADDRESS_VALUE[7:0]: Value
The Address Value feature can be used to further customize the power-up defaults for the XR21B1411 before
a software driver begins to initialize the device. For example, the manufacturer, product and serial number
strings can be customized using the address value feature. However, if improperly used, this feature may
cause permanent functional damage in the device.
Send an e-mail to [e-mail] if there is any interest in customizing register default values that
can not be initialized in the Exar I/O Lab web configuration tool.
3.2.1.11
3.2.1.12
3.2.1.13
These bits are reserved and should remain ’0’
Bit[5] of the bmAttributes field of the device descriptor. If OTP_VALID.USB is set to 1, then this bit is set to
indicate that the device supports remote wakeup.
USB_ATTRIBUTES (Read / Write OTP)
USB_MAXPOWER (Read / Write OTP)
ADDRESS VALUE (Read / Write OTP)
25
ENHANCED 1-CH FULL-SPEED USB UART
XR21B1411