C509-L_97 SIEMENS [Siemens Semiconductor Group], C509-L_97 Datasheet - Page 169

• Manufacturer Part Number: C509-L_97
• Description: 8-Bit CMOS Microcontroller
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

Special Function Register S1CON (Address 9B H )
Special Function Register S1BUF (Address 9C H )
Bit
SM
S1P
SM21
REN1
TB81
RB81
TI1
RI1
Semiconductor Group
Bit No.
9C H
9B H
MSB
SM
7
7
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.
S1P
6
6
Serial Interface 1 Buffer Register
SM21
5
5
REN1
4
4
6-91
TB81
3
3
On-Chip Peripheral Components
RB81
2
2
TI1
1
1
Reset Value : 01000000 B
LSB
RI1
0
0
Reset Value : XX H
S1BUF
S1CON
1997-10-01
C509-L