C509-L_97 Datasheet, PDF (169/290 Pages) Siemens Semiconductor Group – 8-Bit CMOS Microcontroller

On-Chip Peripheral Components
C509-L
Special Function Register S1CON (Address 9BH)
Special Function Register S1BUF (Address 9CH)
Reset Value : 01000000B
Reset Value : XXH
Bit No.
9BH
MSB
7
SM
LSB
6
5
4
3
2
1
0
S1P SM21 REN1 TB81 RB81 TI1 RI1 S1CON
7
9CH
6
5
4
3
2
1
Serial Interface 1 Buffer Register
0
S1BUF
Bit
SM
S1P
SM21
REN1
TB81
RB81
TI1
RI1
Function
Serial port 1 mode select bit
SM = 0: Serial mode A; 9-bit UART
SM = 1: Serial mode B; 8-bit UART
Serial interface 1 prescaler
When set (default after reset), an additional prescaler by 2 is active at
the serial interface 1 baud rate generator.
Enable serial port 1 multiprocessor communication in mode A
If SM21 is set to 1 in mode A, RI1 will not be activated if the received 9th
data bit (RB81) is 0. In mode B, if SM21 = 1, RI1 will not be activated if
a valid stop bit was not received.
Enable receiver of serial port 1
Set by software to enable serial reception. Cleared by software to
disable reception.
Serial port 1 transmitter bit 9
TB81 is the 9th data bit that will be transmitted in mode A. Set or cleared
by software as desired.
Serial port 1 receiver bit 9
RB81 is the 9th data bit that was received in mode A. In mode B,
if SM21 = 0, RB81 is the stop bit that was received.
Serial port 1 transmitter interrupt flag
TI1 is set by hardware at the beginning of the stop bit in any serial
transmission. TI1 must be cleared by software.
Serial port 1 receiver interrupt flag
RI1 is set by hardware at the halfway through the stop bit time in any
serial reception. RI1 must be cleared by software.
Semiconductor Group
6-91
1997-10-01