STC micro STC8A8K64D4 Series - UART4 Mode 1

STC8A8K64D4 Series Manual
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data transmitting pin, and RxD4 is the data receiving pin, the serial port is a full duplex receiver/transmitter.
Write
S4BUF
TxD4
S4TI
D0 D1 D2 D3 D4 D5 D6 D7Start Stop
Transmitting data (UART4 mode 0)
Write
S4CON
RxD4
S4RI
D0 D1 D2 D3 D4 D5 D6 D7Start Stop
S4REN=1, S4RI=0
Receiving data (UART4 mode 0)
The baud rate of UART4 is variable. It is generated by T2 or T4. If the timer is in 1T mode (12x speed), the
corresponding baud rate is increased by 12 times.
The baud rate of UART4 mode 0 is calculated as follows, where SYSclk is the system operating frequency.
Timer selected
Speed of timer
Baud rate calculation formula
T2
1T
   

  
12T
   

    
T4
1T
   

  
12T
   

    
14.6.4 UART4 Mode 1
UART4 operating in mode 1 is a 9-bit data UART mode with variable baud rate. One frame data consists of 11
bits: 1 start bit, 8 data bits (LSB first), 1 programmable bit (9
th
bit) and 1 stop bit. The baud rate is variable, which can
be set by the software as needed. TxD4 is the data transmitting pin, and RxD4 is the data receiving pin, the serial port
is a full duplex receiver/transmitter.
Write
S4BUF
TxD4
S4TI
D0 D1 D2 D3 D4 D5 D6 D7Start Stop
Transmitting data (UART4 mode 1)
TB8