XR21V1410 Datasheet, PDF (20/23 Pages) Exar Corporation – 1-CH FULL-SPEED USB UART

XR21V1410
1-CH FULL-SPEED USB UART
REV. 1.0.0
GPIO_MODE[3]: Transceiver Enable Polarity
• Logic 0 = Low for TX
• Logic 1 = High for TX
GPIO_MODE[7:4]: Reserved
These register bits are reserved. When writing to these bits, the value should be ’0’. When reading from these
bits, they are undefined and should be ignored.
3.3.12 GPIO_DIRECTION Register Description (Read/Write)
This register controls the direction of the GPIO if it is not controlled by the GPIO_MODE register.
GPIO_DIRECTION[5:0]: GPIOx Direction
• Logic 0 = GPIOx is an input.
• Logic 1 = GPIOx is an output.
GPIO_DIRECTION[7:6]: Reserved
These register bits are reserved and should be ’0’.
3.3.13 GPIO_SET Register Description (Read/Write)
Writing a ’1’ in this register drives the GPIO output high. Writing a ’0’ to a bit has no effect. Bits 7-6 are unused
and should be ’0’.
3.3.14 GPIO_CLEAR Register Description (Read/Write)
Writing a ’1’ in this register drives the GPIO output low. Writing a ’0’ to a bit has no effect. Bits 7-6 are unused
and should be ’0’.
3.3.15 GPIO_STATUS Register Description (Read-Only)
This register reports the current state of the GPIO pin.
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