XR21B1420IL28-0A Datasheet, PDF (32/60 Pages) Exar Corporation – Enhanced 1-Ch Full-Speed USB UART

XR21B1420
TX_FIFO_COUNT (0x041) - Read Only
This register is used to read the number of bytes currently in the transmit FIFO.
Bit
15:10
9:0
Default
Description
0
Reserved
These bits are reserved and should be written as ‘0’.
0
Count
Reports the number of bytes currently in the TX FIFO.
TX_WIDE_MODE (0x042) - Read/Write
This register is used to enable the Wide Mode for the Transmitter.
Bit
15:1
0
Default
Description
0
Reserved
These bits are reserved and should be written as ‘0’.
0
Enable
0: Normal (5, 6, 7, 8 or 9 bit data) mode
1: Wide mode See “Wide Mode Transmit” on page 11, “Wide mode receive operation with 5, 6, 7 or 8-bit data”
on page 11 and “Wide mode receive operation with 9-bit data” on page 12.
RX_FIFO_FLUSH (0x043) - Write Only
This register is used to flush the receive FIFO.
Bit
15:3
2
1
0
Default
Description
0
Reserved
These bits are reserved and should be written as ‘0’.
0
AUTO_CLOSE
0: No effect on the RX FIFO when the UART port RX is disabled
1: The RX FIFO is automatically flushed when the UART port RX is disabled
1
AUTO_OPEN
0: No effect on the RX FIFO when the UART port RX is enabled
1: The RX FIFO is automatically flushed when the UART port RX is enabled
0
Reset
0: No effect on the RX FIFO
1: Resets the RX FIFO, self-clearing
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Rev 1A