NuMicro® NUC029LEE/NUC029SEE32-bit Arm® Cortex® -M0 MicrocontrollerAug, 2018 Page 346 of 497 Rev 1.00NUMICRO® NUC029LEE/NUC029SEE TECHNICAL REFERENCE MANUALSetting LEV_RTS(UA_MCR[9]) can control the RTS pin output is inverse or non-inverse fromRTS signal. User can read the RTS_ST(UA_MCR[13]) bit to get real RTS pin output voltage logicstatus.LEV_RTS = 1LEV_RTS = 0nRTS Signal(internal signal)ActiveRTS pin output status of UART function mode (RTS auto-flow control enabled)Byte (i) Byte (i+n)StartbitRX pin input(from external)RTS inactivedelayExternaldelayStartbitRX_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 EnabledAs shown in the Figure 6.13-7, in software mode (AUTO_RTS_EN(UA_IER[12])=0) the RTS flowis 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 fromRTS(UA_MCR[1]) control bit. User can read the RTS_ST(UA_MCR[13]) bit to get real RTS pinoutput voltage logic status.LEV_RTS = 1LEV_RTS = 0RTS control bit(UA_MCR[1])RTS_ST(UA_MCR[13]),RTS pin outputActiveRTS pin output status of UART function modeSet UA_MCR[1] = 0 by softwave Set UA_MCR[1] = 1 by softwave(default)Figure 6.13-7 UART RTS Flow with Software Control6.13.5.7 IrDA Function ModeThe UART Controller also provides Serial IrDA (SIR, Serial Infrared) function (user must setUA_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 stopbit. The maximum data rate is 115.2 kbps. The IrDA SIR block contains an IrDA SIR protocolencoder/decoder. The IrDA SIR protocol is half-duplex only. So it cannot transmit and receivedata at the same time. The IrDA SIR physical layer specifies a minimum 10 ms transfer delay
