XR21V1412

6

2-CH FULL-SPEED USB UART

REV. 1.0.0

1.0 FUNCTIONAL DESCRIPTIONS

1.1

USB interface

The USB interface of the V1412 is compliant with the USB 2.0 Full-Speed Specifications. The USB

configuration model presented by the V1412 to the device driver is compatible to the Abstract Control Model of

the USB Communication Device Class (CDC-ACM). The V1412 uses the following set of parameters:

1.1.1

USB Vendor ID

Exar’s USB Vendor ID is 0x04E2. This is the default Vendor ID that is used for the V1412 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 V1412 is 0x1412. 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 V1412 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.

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

SDA

SCL