SAH-C515 SIEMENS [Siemens Semiconductor Group], SAH-C515 Datasheet - Page 88

• Manufacturer Part Number: SAH-C515
• Description: 8-Bit CMOS Microcontroller
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

Figure 6-23
Baud Rate Generation for the Serial Port
Depending on the programmed operating mode different paths are selected for the baud rate clock
generation. Figure 6-23 shows the dependencies of the serial port 0 baud rate clock generation
from the two control bits and from the mode which is selected in the special function register SCON.
6.3.3.1
The baud rate in mode 0 is fixed to :
6.3.3.2
The baud rate in mode 2 depends on the value of bit SMOD in special function register PCON. If
SMOD = 0 (which is the value after reset), the baud rate is 1/64 of the oscillator frequency. If SMOD
= 1, the baud rate is 1/32 of the oscillator frequency.
Semiconductor Group
f
Timer
Overflow
Note: The switch configuration shows the reset state.
OSC
/2
Baud Rate in Mode 0
Baud Rate in Mode 2
1
÷ 39
÷ 6
Mode 2 baud rate =
Mode 0 baud rate =
0
1
Mode
Mode
ADCON.7
(BD)
2
0
Mode 1
Mode
3
2
Only one mode
can be selected
64
SMOD
6-45
oscillator frequency
SCON.7
SCON.6
(SM0/
SM1)
x
oscillator frequency
On-Chip Peripheral Components
12
÷ 2
0
1
PCON.7
(SMOD)
MCB03206
Baud
Rate
Clock
C515