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NuMicro® NUC029LEE/NUC029SEE
32-bit Arm
®
Cortex
®
-M0 Microcontroller
Aug, 2018
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346
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497
Rev 1.00
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UC029
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ICA
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Setting LEV_RTS(UA_MCR[9]) can control the RTS pin output is inverse or non-inverse from
RTS signal. User can read the RTS_ST(UA_MCR[13]) bit to get real RTS pin output voltage logic
status.
LEV_RTS = 1
LEV_RTS = 0
nRTS Signal
(internal signal)
Active
RTS pin output status of UART function mode (RTS auto-flow control enabled)
Byte (i)
Byte (i+n)
Start
bit
RX pin input
(from external)
RTS inactive
delay
External
delay
Start
bit
RX_POINTER
(UA_FSR[13:18])
RTS_TRI_LEV
(UA_FCR[19:16])
<
RX_POINTER
(UA_FSR[13:18])
RTS_TRI_LEV
(UA_FCR[19:16])
=
RTS_ST
(UA_MCR[13]),
RTS pin output
(default)
Figure 6.13-6 UART RTS Auto Flow Control Enabled
As shown in the Figure 6.13-7, in software mode (AUTO_RTS_EN(UA_IER[12])=0) the RTS flow
is directly controlled by software programming of RTS(UA_MCR[1]) control bit.
Setting LEV_RTS(UA_MCR[9]) can control the RTS pin output is inverse or non-inverse from
RTS(UA_MCR[1]) control bit. User can read the RTS_ST(UA_MCR[13]) bit to get real RTS pin
output voltage logic status.
LEV_RTS = 1
LEV_RTS = 0
RTS control bit
(UA_MCR[1])
RTS_ST
(UA_MCR[13]),
RTS pin output
Active
RTS pin output status of UART function mode
Set UA_MCR[1] = 0 by softwave
Set UA_MCR[1] = 1 by softwave
(default)
Figure 6.13-7 UART RTS Flow with Software Control
6.13.5.7 IrDA Function Mode
The UART Controller also provides Serial IrDA (SIR, Serial Infrared) function (user must set
UA_FUN_SEL [1:0] to ’10’ to enable the IrDA function). The SIR specification defines a short-
range infrared asynchronous serial transmission mode with one start bit, 8 data bits, and 1 stop
bit. The maximum data rate is 115.2 kbps. The IrDA SIR block contains an IrDA SIR protocol
encoder/decoder. The IrDA SIR protocol is half-duplex only. So it cannot transmit and receive
data at the same time. The IrDA SIR physical layer specifies a minimum 10 ms transfer delay