UA_RBR

UA_THR

UA_MCR

UA_MSR

UA_FSR

UA_ISR

UA_TOR

UA_BAUD

UA_IRCR

UA_ALT_CSR

UA_FUN_SEL

UA_IER

UA_FCR

UA_LCR

RBR : Receive Buffer Register (Read Only)\nBy reading this register, the UART will return an 8-bit data received from RX pin (LSB first).
bits : 0 - 7 (8 bit)
access : read-only

THR : Transmit Holding Register\nBy writing to this register, the UART will send out an 8-bit data through the TX pin (LSB first).
bits : 0 - 7 (8 bit)
access : write-only

RTS : RTS (Request-To-Send) Signal (Not Available in UART2 Channel)\n
bits : 1 - 1 (1 bit)
access : read-write

Enumeration:

End of enumeration elements list.

LEV_RTS : RTS Trigger Level (Not Available in UART2 Channel)\nThis bit can change the RTS trigger level.\n
bits : 9 - 9 (1 bit)
access : read-write

Enumeration:

End of enumeration elements list.

RTS_ST : RTS Pin State (Read Only) (Not Available in UART2 Channel)\nThis bit is the output pin status of RTS.
bits : 13 - 13 (1 bit)
access : read-only

DCTSF : Detect CTS State Change Flag (Read Only) (Not Available in UART2 Channel)\nThis bit is set whenever CTS input has change state, and it will generate Modem interrupt to CPU when UA_IER [MODEM_IEN] is set to 1.\nWrite 1 to clear this bit to 0.
bits : 0 - 0 (1 bit)
access : read-only

CTS_ST : CTS Pin Status (Read Only) (Not Available in UART2 Channel)\nThis bit is the pin status of CTS.
bits : 4 - 4 (1 bit)
access : read-only

LEV_CTS : CTS Trigger Level (Not Available in UART2 Channel)\nThis bit can change the CTS trigger level.\n
bits : 8 - 8 (1 bit)
access : read-write

Enumeration:

End of enumeration elements list.

RX_OVER_IF : RX Overflow Error IF (Read Only)\nThis bit is set when RX FIFO overflow.\nIf the number of bytes of received data is greater than RX_FIFO (UA_RBR) size, 64/16 bytes of UART0/UART1, this bit will be set.\nNote: This bit is read only, but can be cleared by writing '1' to it.
bits : 0 - 0 (1 bit)
access : read-only

RS485_ADD_DETF : RS-485 Address Byte Detection Flag (NuMicro( NUC100/NUC120Low Density Only)\nNote: This field is used for RS-485 function mode.\nNote: This bit is read only, but can be cleared by writing '1' to it.
bits : 3 - 3 (1 bit)
access : read-write

PEF : Parity Error Flag (Read Only) This bit is set to logic 1 whenever the received character does not have a valid parity bit , and is reset whenever the CPU writes 1 to this bit. Note: This bit is read only, but can be cleared by writing '1' to it.
bits : 4 - 4 (1 bit)
access : read-only

FEF : Framing Error Flag (Read Only) This bit is set to logic 1 whenever the received character does not have a valid stop bit (that is, the stop bit following the last data bit or parity bit is detected as logic 0), and is reset whenever the CPU writes 1 to this bit. Note: This bit is read only, but can be cleared by writing '1' to it.
bits : 5 - 5 (1 bit)
access : read-only

BIF : Break Interrupt Flag (Read Only) This bit is set to a logic 1 whenever the received data input(RX) is held in the spacing state (logic 0) for longer than a full word transmission time (that is, the total time of start bit + data bits + parity + stop bits) and is reset whenever the CPU writes 1 to this bit. Note:Note: This bit is read only, but can be cleared by writing '1' to it.
bits : 6 - 6 (1 bit)
access : read-only

RX_POINTER : RX FIFO Pointer (Read Only)\nThis field indicates the RX FIFO Buffer Pointer. When UART receives one byte from external device, RX_POINTER increases one. When one byte of RX FIFO is read by CPU, RX_POINTER decreases one.
bits : 8 - 13 (6 bit)
access : read-only

RX_EMPTY : Receiver FIFO Empty (Read Only)\nThis bit initiates RX FIFO empty or not.\nWhen the last byte of RX FIFO has been read by CPU, hardware sets this bit high. It will be cleared when UART receives any new data.
bits : 14 - 14 (1 bit)
access : read-only

TX_POINTER : TX FIFO Pointer (Read Only)\nThis field indicates the TX FIFO Buffer Pointer. When CPU writes one byte into UA_THR, TX_POINTER increases one. When one byte of TX FIFO is transferred to Transmitter Shift Register, TX_POINTER decreases one.
bits : 16 - 21 (6 bit)
access : read-only

TX_EMPTY : Transmitter FIFO Empty (Read Only)\nThis bit indicates TX FIFO empty or not.\nWhen the last byte of TX FIFO has been transferred to Transmitter Shift Register, hardware sets this bit high. It will be cleared when writing data into THR (TX FIFO not empty).
bits : 22 - 22 (1 bit)
access : read-only

TX_OVER_IF : TX Overflow Error Interrupt Flag (Read Only)\nIf TX FIFO (UA_THR) is full, an additional write to UA_THR will cause this bit to logic 1. \nNote: This bit is read only, but can be cleared by writing '1' to it.
bits : 24 - 24 (1 bit)
access : read-only

TE_FLAG : Transmitter Empty Flag (Read Only)\nBit is set by hardware when TX FIFO (UA_THR) is empty and the STOP bit of the last byte has been transmitted.\nBit is cleared automatically when TX FIFO is not empty or the last byte transmission has not completed.
bits : 28 - 28 (1 bit)
access : read-only

RDA_IF : Receive Data Available Interrupt Flag (Read Only).\nWhen the number of bytes in the RX FIFO equals the RFITL then the RDA_IF will be set. If UA_IER [RDA_IEN] is enabled, the RDA interrupt will be generated. \nNote: This bit is read only and it will be cleared when the number of unread bytes of RX FIFO drops below the threshold level (RFITL).
bits : 0 - 0 (1 bit)
access : read-only

THRE_IF : Transmit Holding Register Empty Interrupt Flag (Read Only). \nThis bit is set when the last data of TX FIFO is transferred to Transmitter Shift Register. If UA_IER [THRE_IEN] is enabled, the THRE interrupt will be generated.\nNote: This bit is read only and it will be cleared when writing data into THR (TX FIFO not empty).
bits : 1 - 1 (1 bit)
access : read-only

RLS_IF : Receive Line Interrupt Flag (Read Only).\nThis bit is set when the RX receive data have parity error, framing error or break error (at least one of 3 bits, BIF, FEF and PEF, is set). If UA_IER [RLS_IEN] is enabled, the RLS interrupt will be generated.\nNote: This bit is read only and reset to 0 when all bits of BIF, FEF and PEF are cleared.
bits : 2 - 2 (1 bit)
access : read-only

MODEM_IF : MODEM Interrupt Flag (Read Only) (Not Available in UART2 Channel)\nNote: This bit is read only and reset to 0 when bit DCTSF is cleared by a write 1 on DCTSF.
bits : 3 - 3 (1 bit)
access : read-only

TOUT_IF : Time Out Interrupt Flag (Read Only)\nThis bit is set when the RX FIFO is not empty and no activities occurred in the RX FIFO and the time out counter equal to TOIC. If UA_IER [TOUT_IEN] is enabled, the Tout interrupt will be generated. \nNote: This bit is read only and user can read UA_RBR (RX is in active) to clear it.
bits : 4 - 4 (1 bit)
access : read-only

BUF_ERR_IF : Buffer Error Interrupt Flag (Read Only)\nThis bit is set when the TX or RX FIFO overflows or Break Interrupt Flag or Parity Error Flag or Frame Error Flag (TX_OVER_IF or RX_OVER_IF or BIF or PEF or FEF) is set. When BUF_ERR_IF is set, the transfer is not correct. If UA_IER [BUF_ERR_IEN] is enabled, the buffer error interrupt will be generated.
bits : 5 - 5 (1 bit)
access : read-only

RDA_INT : Receive Data Available Interrupt Indicator (Read Only).\nThis bit is set if RDA_IEN and RDA_IF are both set to 1.\n
bits : 8 - 8 (1 bit)
access : read-only

Enumeration:

End of enumeration elements list.

THRE_INT : Transmit Holding Register Empty Interrupt Indicator (Read Only)\nThis bit is set if THRE_IEN and THRE_IF are both set to 1.\n
bits : 9 - 9 (1 bit)
access : read-only

Enumeration:

End of enumeration elements list.

RLS_INT : Receive Line Status Interrupt Indicator (Read Only). \nThis bit is set if RLS_IEN and RLS_IF are both set to 1.\n
bits : 10 - 10 (1 bit)
access : read-only

Enumeration:

End of enumeration elements list.

MODEM_INT : MODEM Status Interrupt Indicator (Read Only) (Not Available in UART2 Channel)\nThis bit is set if MODEM_IEN and MODEM_IF are both set to 1.\n
bits : 11 - 11 (1 bit)
access : read-only

Enumeration:

End of enumeration elements list.

TOUT_INT : Time Out Interrupt Indicator (Read Only)\nThis bit is set if TOUT_IEN and TOUT_IF are both set to 1.\n
bits : 12 - 12 (1 bit)
access : read-only

Enumeration:

End of enumeration elements list.

BUF_ERR_INT : Buffer Error Interrupt Indicator (Read Only)\nThis bit is set if BUF_ERR_IEN and BUF_ERR_IF are both set to 1.\n
bits : 13 - 13 (1 bit)
access : read-only

Enumeration:

End of enumeration elements list.

HW_RLS_IF : In DMA Mode, Receive Line Status Flag (Read Only)\nThis bit is set when the RX receive data have parity error, framing error or break error (at least one of 3 bits, BIF, FEF and PEF, is set). If UA_IER [RLS_IEN] is enabled, the RLS interrupt will be generated.\nNote: This bit is read only and reset to 0 when all bits of BIF, FEF and PEF are cleared.
bits : 18 - 18 (1 bit)
access : read-only

HW_MODEM_IF : In DMA Mode, MODEM Interrupt Flag (Read Only) (Not Available in UART2 Channel)\nNote: This bit is read only and reset to 0 when bit DCTSF is cleared by a write 1 on DCTSF.
bits : 19 - 19 (1 bit)
access : read-only

HW_TOUT_IF : In DMA Mode, Time Out Interrupt Flag (Read Only)\nThis bit is set when the RX FIFO is not empty and no activities occurred in the RX FIFO and the time out counter equal to TOIC. If UA_IER [TOUT_IEN] is enabled, the Tout interrupt will be generated. \nNote: This bit is read only and user can read UA_RBR (RX is in active) to clear it.
bits : 20 - 20 (1 bit)
access : read-only

HW_BUF_ERR_IF : In DMA Mode, Buffer Error Interrupt Flag (Read Only)\nThis bit is set when the TX or RX FIFO overflows (TX_OVER_IF or RX_OVER_IF is set). When BUF_ERR_IF is set, the transfer maybe is not correct. If UA_IER [BUF_ERR_IEN] is enabled, the buffer error interrupt will be generated.\nNote: This bit is cleared when both TX_OVER_IF and RX_OVER_IF are cleared.
bits : 21 - 21 (1 bit)
access : read-only

HW_RLS_INT : In DMA Mode, Receive Line Status Interrupt Indicator (Read Only)\nThis bit is set if RLS_IEN and HW_RLS_IF are both set to 1.\n
bits : 26 - 26 (1 bit)
access : read-only

Enumeration:

End of enumeration elements list.

HW_MODEM_INT : In DMA Mode, MODEM Status Interrupt Indicator (Read Only) (Not Available in UART2 Channel) This bit is set if MODEM_IEN and HW_MODEM_IF are both set to 1.
bits : 27 - 27 (1 bit)
access : read-only

Enumeration:

End of enumeration elements list.

HW_TOUT_INT : In DMA Mode, Time Out Interrupt Indicator (Read Only)\nThis bit is set if TOUT_IEN and HW_TOUT_IF are both set to 1.\n
bits : 28 - 28 (1 bit)
access : read-only

Enumeration:

End of enumeration elements list.

HW_BUF_ERR_INT : In DMA Mode, Buffer Error Interrupt Indicator (Read Only)\nThis bit is set if BUF_ERR_IEN and HW_BUF_ERR_IF are both set to 1.\n
bits : 29 - 29 (1 bit)
access : read-only

Enumeration:

End of enumeration elements list.

TOIC : Time Out Interrupt Comparator\n
bits : 0 - 7 (8 bit)
access : read-write

DLY : TX Delay Time Value (NuMicro( NUC100/NUC120 Low Density Only)\nThis field is use to programming the transfer delay time between the last stop bit and next start bit.
bits : 8 - 15 (8 bit)
access : read-write

BRD : Baud Rate Divider\nThe field indicates the baud rate divider.
bits : 0 - 15 (16 bit)
access : read-write

DIVIDER_X : Divider X\n
bits : 24 - 27 (4 bit)
access : read-write

DIV_X_ONE : Divider X Equal to 1\nRefer to the Table 513 below for more information.
bits : 28 - 28 (1 bit)
access : read-write

Enumeration:

End of enumeration elements list.

DIV_X_EN : Divider X Enable\nRefer to the table below for more information.\nNote: In IrDA mode, this bit must be disabled.
bits : 29 - 29 (1 bit)
access : read-write

Enumeration:

End of enumeration elements list.

TX_SELECT : TX_SELECT\n
bits : 1 - 1 (1 bit)
access : read-write

Enumeration:

End of enumeration elements list.

INV_TX : INV_TX\n
bits : 5 - 5 (1 bit)
access : read-write

Enumeration:

End of enumeration elements list.

INV_RX : INV_RX\n
bits : 6 - 6 (1 bit)
access : read-write

Enumeration:

End of enumeration elements list.

RS485_NMM : RS-485 Normal Multi-drop Operation Mode (NMM) (NuMicro( NUC100/NUC120 Low Density Only)\nNote: It can't be active with RS-485_AAD operation mode.
bits : 8 - 8 (1 bit)
access : read-write

Enumeration:

End of enumeration elements list.

RS485_AAD : RS-485 Auto Address Detection Operation Mode (AAD) (NuMicro( NUC100/NUC120 Low Density Only)\nNote: It can't be active with RS-485_NMM operation mode.
bits : 9 - 9 (1 bit)
access : read-write

Enumeration:

End of enumeration elements list.

RS485_AUD : RS-485 Auto Direction Mode (AUD) (NuMicro( NUC100/NUC120 Low Density Only)\nNote: It can be active with RS-485_AAD or RS-485_NMM operation mode.
bits : 10 - 10 (1 bit)
access : read-write

Enumeration:

End of enumeration elements list.

RS485_ADD_EN : RS-485 Address Detection Enable (NuMicro( NUC100/NUC120 Low Density Only)\nThis bit is use to enable RS-485 address detection mode. \nNote: This field is used for RS-485 any operation mode.
bits : 15 - 15 (1 bit)
access : read-write

Enumeration:

End of enumeration elements list.

ADDR_MATCH : Address Match Value Register (NuMicro( NUC100/NUC120 Low Density Only)\nThis field contains the RS-485 address match values.\nNote: This field is used for RS-485 auto address detection mode.
bits : 24 - 31 (8 bit)
access : read-write

FUN_SEL : Function Select Enable\n
bits : 0 - 1 (2 bit)
access : read-write

Enumeration:

End of enumeration elements list.

RDA_IEN : Receive Data Available Interrupt Enable.\n
bits : 0 - 0 (1 bit)
access : read-write

Enumeration:

End of enumeration elements list.

THRE_IEN : Transmit Holding Register Empty Interrupt Enable\n
bits : 1 - 1 (1 bit)
access : read-write

Enumeration:

End of enumeration elements list.

RLS_IEN : Receive Line Status Interrupt Enable \n
bits : 2 - 2 (1 bit)
access : read-write

Enumeration:

End of enumeration elements list.

MODEM_IEN : Modem Status Interrupt Enable (Not Available in UART2 Channel)\n
bits : 3 - 3 (1 bit)
access : read-write

Enumeration:

End of enumeration elements list.

RTO_IEN : RX Time Out Interrupt Enable\n
bits : 4 - 4 (1 bit)
access : read-write

Enumeration:

End of enumeration elements list.

BUF_ERR_IEN : Buffer Error Interrupt Enable\n
bits : 5 - 5 (1 bit)
access : read-write

Enumeration:

End of enumeration elements list.

WAKE_EN : UART Wake-up Function Enable (Not Available in UART2 Channel)\n
bits : 6 - 6 (1 bit)
access : read-write

Enumeration:

End of enumeration elements list.

TIME_OUT_EN : Time Out Counter Enable\n
bits : 11 - 11 (1 bit)
access : read-write

Enumeration:

End of enumeration elements list.

AUTO_RTS_EN : RTS Auto Flow Control Enable (Not Available in UART2 Channel)\nWhen RTS auto-flow is enabled, if the number of bytes in the RX FIFO equals the UA_FCR [RTS_TRI_LEV], the UART will de-assert RTS signal.
bits : 12 - 12 (1 bit)
access : read-write

Enumeration:

End of enumeration elements list.

AUTO_CTS_EN : CTS Auto Flow Control Enable (Not Available in UART2 Channel)\nWhen CTS auto-flow is enabled, the UART will send data to external device when CTS input assert (UART will not send data to device until CTS is asserted).
bits : 13 - 13 (1 bit)
access : read-write

Enumeration:

End of enumeration elements list.

DMA_TX_EN : TX DMA Enable (Not Available in UART2 Channel)\nThis bit can enable or disable TX DMA service.\n
bits : 14 - 14 (1 bit)
access : read-write

Enumeration:

End of enumeration elements list.

DMA_RX_EN : RX DMA Enable (Not Available in UART2 Channel)\nThis bit can enable or disable RX DMA service.\n
bits : 15 - 15 (1 bit)
access : read-write

Enumeration:

End of enumeration elements list.

RFR : RX Field Software Reset\nWhen RX_RST is set, all the byte in the receiver FIFO and RX internal state machine are cleared.\nNote: This bit will automatically clear at least 3 UART engine clock cycles.
bits : 1 - 1 (1 bit)
access : read-write

Enumeration:

End of enumeration elements list.

TFR : TX Field Software Reset\nWhen TX_RST is set, all the byte in the transmit FIFO and TX internal state machine are cleared.\nNote: This bit will automatically clear at least 3 UART engine clock cycles.
bits : 2 - 2 (1 bit)
access : read-write

Enumeration:

End of enumeration elements list.

RFITL : RX FIFO Interrupt (INT_RDA) Trigger Level\n
bits : 4 - 7 (4 bit)
access : read-write

RX_DIS : Receiver Disable Register. The receiver is disabled or not (set 1 to disable receiver) Note: This field is used for RS-485 Normal Multi-drop mode. It should be programmed before UA_ALT_CSR [RS-485_NMM] is programmed.
bits : 8 - 8 (1 bit)
access : read-write

Enumeration:

End of enumeration elements list.

RTS_TRI_LEV : RTS Trigger Level for Auto-flow Control Use (Not Available in UART2 Channel)\n
bits : 16 - 19 (4 bit)
access : read-write

WLS : Word Length Selection\n
bits : 0 - 1 (2 bit)
access : read-write

NSB : Number of STOP bit
bits : 2 - 2 (1 bit)
access : read-write

Enumeration:

End of enumeration elements list.

PBE : Parity Bit Enable\n
bits : 3 - 3 (1 bit)
access : read-write

Enumeration:

End of enumeration elements list.

EPE : Even Parity Enable\nThis bit has effect only when bit 3 (parity bit enable) is set.
bits : 4 - 4 (1 bit)
access : read-write

Enumeration:

End of enumeration elements list.

SPE : Stick Parity Enable\n
bits : 5 - 5 (1 bit)
access : read-write

Enumeration:

End of enumeration elements list.

BCB : Break Control Bit\nWhen this bit is set to logic 1, the serial data output (TX) is forced to the Spacing State (logic 0). This bit acts only on TX and has no effect on the transmitter logic.
bits : 6 - 6 (1 bit)
access : read-write