Owners manual

Interfaces
H3 Datasheet(Revision1.2) Copyright© 2015 Allwinner Technology Co.,Ltd.All Rights Reserved. Page 476
This bit is cleared when the RBR is read in non-FIFO mode, or when the
receiver FIFO is empty, in FIFO mode.
8.3.5.11. UART Modem Status Register(Default Value: 0x00000000)
Offset: 0x0018
Register Name: UART_MSR
Bit
R/W
Default/Hex
Description
31:8
/
/
/
7
R
0
DCD
Line State of Data Carrier Detect
This is used to indicate the current state of the modem control line dcd_n.
This bit is the complement of dcd_n. When the Data Carrier Detect input
(dcd_n) is asserted it is an indication that the carrier has been detected by
the modem or data set.
0: dcd_n input is de-asserted (logic 1)
1: dcd_n input is asserted (logic 0)
6
R
0
RI
Line State of Ring Indicator
This is used to indicate the current state of the modem control line ri_n. This
bit is the complement of ri_n. When the Ring Indicator input (ri_n) is
asserted it is an indication that a telephone ringing signal has been received
by the modem or data set.
0: ri_n input is de-asserted (logic 1)
1: ri_n input is asserted (logic 0)
5
R
0
DSR
Line State of Data Set Ready
This is used to indicate the current state of the modem control line dsr_n.
This bit is the complement of dsr_n. When the Data Set Ready input (dsr_n)
is asserted it is an indication that the modem or data set is ready to establish
communications with UART.
0: dsr_n input is de-asserted (logic 1)
1: dsr_n input is asserted (logic 0)
In Loopback Mode (MCR[4] set to one), DSR is the same as MCR[0] (DTR).
4
R
0
CTS
Line State of Clear To Send
This is used to indicate the current state of the modem control line cts_n.
This bit is the complement of cts_n. When the Clear to Send input (cts_n) is
asserted it is an indication that the modem or data set is ready to exchange
data with UART.
0: cts_n input is de-asserted (logic 1)
1: cts_n input is asserted (logic 0)
In Loopback Mode (MCR[4] = 1), CTS is the same as MCR[1] (RTS).
3
R
0
DDCD
Delta Data Carrier Detect
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