xr21b1411 Exar Corporation, xr21b1411 Datasheet - Page 21

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

REV. 1.1.0
LOOPBACK[1]: RTS_CTS
When this bit is set RTS is looped back to CTS.
LOOPBACK[2]: DTR_DSR
When this bit is set DTR is looped back to DSR.
LOOPBACK[11:3]: Reserved
These bits are reserved and should remain ’0’.
TX_FIFO_RESET[0]: Reset
TX_FIFO_RESET[11:1]: Reserved
These bits are reserved and should remain ’0’.
TX_FIFO_COUNT[7:0]: Character Count
TX_FIFO_COUNT[11:8]: Reserved
These bits are reserved and should remain ’0’.
RX_FIFO_RESET[0]: Reset
RX_FIFO_RESET[11:1]: Reserved
These bits are reserved and should remain ’0’.
RX_FIFO_COUNT[8:0]: Character Count
RX_FIFO_RESET[11:9]: Reserved
These bits are reserved and should remain ’0’.
RX_FIFO_LOW_LATENCY[0]: Low Latency Enable
This register is automatically set to logic ’1’ for baud rates below 40961 bps.
3.1.1.23
3.1.1.24
3.1.1.25
3.1.1.26
3.1.1.27
Logic 0 = Disable loopback.
Logic 1 = Enable loopback.
Logic 0 = Disable loopback.
Logic 1 = Enable loopback.
Write a ’1’ to reset the Tx FIFO, self-clearing.
Reports the number of characters currently in the Tx FIFO.
Write a ’1’ to reset the Rx FIFO, self-clearing.
Reports the number of characters currently in the Rx FIFO.
Logic 0 = Receive data is not from Rx FIFO until bMaxPacketSize (normally 64 bytes) or timeout (3
characters) has been reached. (Note: When the CDC-ACM driver is used, the bMaxPacketSize becomes
63 bytes.)
Logic 1 = Receive data is forwarded from Rx FIFO immediately upon receipt.
TX_FIFO_RESET (Write Only)
TX_FIFO_COUNT (Read Only)
RX_FIFO_RESET (Write Only)
RX_FIFO_COUNT (Read Only)
RX_FIFO_LOW_LATENCY (Read / Write)
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ENHANCED 1-CH FULL-SPEED USB UART
XR21B1411