XR21V1414 Datasheet, PDF (8/26 Pages) Exar Corporation – 4-CH FULL-SPEED USB UART

XR21V1414
4-CH FULL-SPEED USB UART
REV. 1.0.0
1.0 FUNCTIONAL DESCRIPTIONS
1.1 USB interface
The USB interface of the V1414 is compliant with the USB 2.0 Full-Speed Specifications. The USB
configuration model presented by the V1414 to the device driver is compatible to the Abstract Control Model of
the USB Communication Device Class (CDC-ACM). The V1414 uses the following set of parameters:
• 1 Control Endpoint
■ Endpoint 0 as outlined in the USB specifications
• 1 Configuration is supported
• 2 interfaces per UART channel
■ Each UART channel has a single interrupt endpoint
■ Each UART channel have bulk-in and bulk-out endpoints
1.1.1 USB Vendor ID
Exar’s USB Vendor ID is 0x04E2. This is the default Vendor ID that is used for the V1414 unless a valid
EEPROM is present on the I2C interface signals. If a valid EEPROM is present, the Vendor ID from the
EEPROM will be used.
1.1.2 USB Product ID
The default USB Product ID for the V1414 is 0x1414. If a valid EEPROM is present, the Product ID from the
EEPROM will be used.
1.2 I2C Interface
The I2C interface provides connectivity to an external I2C memory device (i.e. EEPROM) that can be read by
the V1414 for configuration.
The SDA and SCL are used to specify whether Remote Wakeup and/or Bus Powered configurations are to be
supported. These pins are sampled at power-up. The following table describes how Remote Wakeup and Bus
Powered support.
TABLE 1: REMOTE WAKEUP AND POWER MODES
SDA
SCL
REMOTE WAKE-UP
SUPPORT
POWER MODE
COMMENTS
1
1
No
Self-Powered
Default, if no EEPROM is present
1
0
No
Bus-Powered
0
1
Yes
Self-Powered
0
0
Yes
Bus-Powered
8