Universal Asynchronous Receiver/Transmitter (UART)
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289
0: DTR is logic 1
1: DTR is logic 0
This bit controls the DTR_ output. When bit 0 is set to logic 1, the DTR_ output is forced to
logic 0; When bit 0 is reset to logic 0, the DTR_ output is forced to logic 1.
14.2.5
LSR
Name:
Line Status Register
Size:
32 bits
Address offset:
0x0014
Read/write access:
read-only
31
30
29
…
10
9
8
RSVD
7
6
5
4
3
2
1
0
RXFIFO_ERR
RSVD
TXFIFO_EMPTY
BREAK_ERR_INT
FRAMING_ERR
PARITY_ERR
OVERRUN_ERR
RXFIFO_DATARDY
R
R
R
R
R
R
R
Bit
Name
Access
Reset
Description
31:
8
RSVD
N/A
-
Reserved
7
RXFIFO_ERR
R
0
UART Rx FIFO error
This bit is set when there is at least one parity error, framing error or break indication in
the FIFO. This bit is cleared when the CPU reads the LSR, if there are no subsequent
errors in the FIFO.
6
RSVD
N/A
-
Reserved
5
TXFIFO_EMPTY
R
1
Tx FIFO empty indicator
4
BREAK_ERR_INT
R
0
Break Interrupt (BI) indicator
0: No break condition in the current character.
1: Sets to logic 1 whenever the received data input is held in the spacing (logic 0)
state for a longer than a full word transmission time.
3
FRAMING_ERR
R
0
Framing Error (FE) indicator
0: No framing error in the current character.
1: The received character at the top of the FIFO doesn’t have a valid stop bit.
2
PARITY_ERR
R
0
Parity Error (PE) indicator
0: No parity error in current character.
1: Indicates that the received data character doesn’t have the correct even or odd
parity, as selected by the even-parity-select bit.
1
OVERRUN_ERR
R
0
Overrun Error (OE) indicator
0: No overrun state
1: Indicates that the next character is transferred into the Rx FIFO when the Rx FIFO
is full, thereby destroying the previous character.
0
RXFIFO_DATARDY R
0
Data Ready (DR) indicator
0: No characters in the Receiver FIFO.
1: At least one character has been received and transferred into the FIFO.
14.2.6
MSR
Name:
Modem Status Register
Size:
32 bits
Address offset:
0x0018
Read/write access:
read-only
31
30
29
…
10
9
8
RSVD
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2019-05-15 10:08:03