Holtek BS66F340 - Page 173

Rev. 1.60 172 August 20, 2019 Rev. 1.60 173 August 20, 2019
BS66F340/BS66F350/BS66F360/BS66F370
Touch A/D Flash MCU with LED Driver
BS66F340/BS66F350/BS66F360/BS66F370
Touch A/D Flash MCU with LED Driver
• TXR_RXR Register
The TXR_RXR register is the data register which is used to store the data to be transmitted on the
TX pin or being received from the RX pin.
Bit 7 6 5 4 3 2 1 0
Name TXRX7 TXRX6 TXRX5 TXRX4 TXRX3 TXRX2 TXRX1 TXRX0
R/W R/W R/W R/W R/W R/W R/W R/W R/W
POR x x x x x x x x
"x": unknown
Bit 7~0 TXRX7~TXRX0: UART Transmit/Receive Data bits
• USR Register
The USR register is the status register for the UART, which can be read by the program to
determine the present status of the UART. All ags within the USR register are read only and further
explanations are given below.
Bit 7 6 5 4 3 2 1 0
Name PERR NF FERR OERR RIDLE RXIF TIDLE TXIF
R/W R R R R R R R R
POR 0 0 0 0 1 0 1 1
Bit 7 PERR: Parity error ag
0: No parity error is detected
1: Parity error is detected
The PERR ag is the parity error ag. When this read only ag is "0", it indicates a
parity error has not been detected. When the ag is "1", it indicates that the parity of
the received word is incorrect. This error ag is applicable only if Parity mode (odd or
even) is selected. The ag can also be cleared by a software sequence which involves
a read to the status register USR followed by an access to the RXR data register.
Bit 6 NF: Noise ag
0: No noise is detected
1: Noise is detected
The NF flag is the noise flag. When this read only flag is "0", it indicates no noise
condition. When the ag is "1", it indicates that the UART has detected noise on the
receiver input. The NF ag is set during the same cycle as the RXIF ag but will not
be set in the case of as overrun. The NF ag can be cleared by a software sequence
which will involve a read to the status register USR followed by an access to the RXR
data register.
Bit 5 FERR: Framing error ag
0: No framing error is detected
1: Framing error is detected
The FERR ag is the framing error ag. When this read only ag is "0", it indicates
that there is no framing error. When the ag is "1", it indicates that a framing error
has been detected for the current character. The ag can also be cleared by a software
sequence which will involve a read to the status register USR followed by an access to
the RXR data register.
Bit 4 OERR: Overrun error ag
0: No overrun error is detected
1: Overrun error is detected
The OERR ag is the overrun error ag which indicates when the receiver buffer has
overowed. When this read only ag is "0", it indicates that there is no overrun error.
When the ag is "1", it indicates that an overrun error occurs which will inhibit further
transfers to the RXR receive data register. The ag is cleared by a software sequence,
which is a read to the status register USR followed by an access to the RXR data
register.