XR22804 Datasheet, PDF (30/47 Pages) Exar Corporation – Hi-Speed USB to 10/100 Ethernet Bridge with 4 UARTs

XR22804
TX_WIDE_MODE (0x062) - Read/Write
Bit
15:1
0
Default
Description
0x0000
0
Reserved
These bits are reserved and should be written as ‘0’.
EN
In wide mode, 2 bytes of data are used to transfer one character. This requires 2 bytes of FIFO space, therefore
the FIFO can hold half as many characters in wide mode. In the TX direction bit 0 of the second byte will be
used as bit 9 of the character, if 9-bit mode is enabled. Bits 7:1 of the second byte are not used.
0: Disable TX wide mode
1: Enable TX wide mode
RX_FIFO_RESET (0x063) - Write Only
Bit
15:1
0
Default
Description
0x0000 Reserved
These bits are reserved and should be written as ‘0’.
000
Reset
0: No effect
1: Resets the RX FIFO to empty
RX_FIFO_FILL (0x064) - Read Only
Bit
15:11
10:0
Default
Description
0x00
Reserved
These bits are reserved and should be written as ‘0’.
0x000
Fill
Number of bytes in the RX FIFO
RX_WIDE_MODE (0x065) - Read/Write
Bit
15:1
0
Default
Description
0x0000
0
Reserved
These bits are reserved and should be written as ‘0’.
EN
In wide mode, 2 bytes of Bulk data are used to transfer one character. This requires 2 bytes of FIFO space,
therefore the FIFO can hold half as many characters in wide mode. In the RX direction, bits 3:0 of the second
byte contain the error flags associated with the character. Bits 7:4 of the second byte are not used.
0: Disable RX wide mode
1: Enable RX wide mode
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