SAB-C509-LM SIEMENS [Siemens Semiconductor Group], SAB-C509-LM Datasheet - Page 51

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

C509-L
For clarification some terms regarding the difference between "baud rate clock" and "baud rate"
should be mentioned. In the asynchronous modes the serial interfaces require a clock rate which is
16 times the baud rate for internal synchronization. Therefore, the baud rate generators/timers have
to provide a "baud rate clock" (output signal in figure 25 and figure 26) to the serial interface
which - there divided by 16 - results in the actual "baud rate". Further, the abrevation f
refers to
OSC
the oscillator frequency (crystal or external clock operation).
The variable baud rates for modes 1 and 3 of the serial interface 0 can be derived from either timer
1 or a decdicated baud rate generator (see figure 25). The variable baud rates for modes A and B
of the serial interface 1 are derived from a decdicated baud rate generator as shown in figure 26.
Figure 25
Serial Interface 0 : Baud Rate Generation Configuration
Figure 26
Serial Interface 1 : Baud Rate Generator Configuration
Semiconductor Group
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