NuMicro® NUC029LEE/NUC029SEE32-bit Arm® Cortex® -M0 MicrocontrollerAug, 2018 Page 338 of 497 Rev 1.00NUMICRO® NUC029LEE/NUC029SEE TECHNICAL REFERENCE MANUALNote: UART0 is equipped with 64 bytes FIFO. UART1/UART2 is equipped with 16 bytes FIFO.Figure 6.13-2 UART Block DiagramEach block is described in detail as follows:TX_FIFOThe transmitter is buffered with a 64/16 byte FIFO to reduce the number of interrupts presented tothe CPU.RX_FIFOThe receiver is buffered with a 64/16 byte FIFO (plus three error bits per byte) to reduce thenumber of interrupts presented to the CPU.TX shift RegisterThis block is the shifting the transmitting data out of serially control.RX shift RegisterThis block is the shifting the receiving data in of serially control.Modem Control RegisterThis register controls the interface to the MODEM or data set (or a peripheral device emulating aMODEM).Baud Rate GeneratorDivide the external clock by the divisor to get the desired baud rate. Refer to baud rate equation.IrDA EncodeThis block is IrDA encode control block.IrDA DecodeThis block is IrDA decode control block.Control and Status RegisterThis field is register set that including the FIFO control registers (UA_FCR), FIFO status registers(UA_FSR), and line control register (UA_LCR) for transmitter and receiver. The time-out controlregister (UA_TOR) identifies the condition of time-out interrupt. This register set also includes theinterrupt enable register (UA_IER) and interrupt status register (UA_ISR) to enable or disable theresponding interrupt and to identify the occurrence of the responding interrupt. There are seventypes of interrupts, transmitter FIFO empty interrupt(THRE_INT), receiver threshold level reachinginterrupt (RDA_INT), line status interrupt (parity error or framing error or break interrupt)(RLS_INT), time-out interrupt (TOUT_INT), MODEM/Wake-up status interrupt (MODEM_INT),Buffer error interrupt (BUF_ERR_INT) and LIN receiver break field detected interrupt (LIN _INT).6.13.4 Basic ConfigurationThe UART Controller function pins are configured in PB_MFP, PD_MFP, ALT_MFP, ALT_MFP1and ALT_MFP2 registers.The UART Controller clock are enabled in UART0_EN(APBCLK[16]) for UART0, UART1_EN(APBCLK[17]) for UART1 and UART2_EN(APBCLK[18]) for UART2.The UART Controller clock source is selected by UART_S(CLKSEL[25:24]).The UART Controller clock prescaler is determined by UART_N(CLKDIV[11:8]).UART Interface Controller Pin description is shown as following:
