SAK-C505L Infineon Technologies AG, SAK-C505L Datasheet - Page 36

• Manufacturer Part Number: SAK-C505L
• Description: 8-bit CMOS Microcontroller
• Manufacturer: Infineon Technologies AG

Serial Interface (USART)
The serial port is full duplex and can operate in four modes (one synchronous mode, three
asynchronous modes) as illustrated in Table 7.
Table 7
USART Operating Modes
Mode
0
1
2
3
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 15) to the serial interface which - divided by
16 - results in the actual “baud rate”. Further, the abbrevation
(crystal or external clock operation).
The variable baud rates for modes 1 and 3 of the serial interface can be derived either from timer 1
or from a dedicated baud rate generator (see Figure 15).
Data Sheet
0
0
1
1
SM0
SCON
0
1
0
1
SM1
Description
Shift register mode, fixed baud rate
Serial data enters and exits through R D; T D outputs the shift clock;
8-bit are transmitted/received (LSB first)
8-bit UART, variable baud rate
10 bits are transmitted (through T D) or received (at R D)
9-bit UART, fixed baud rate
11 bits are transmitted (through T D) or received (at R D)
9-bit UART, variable baud rate
Like mode 2
34
f
OSC
refers to the oscillator frequency
C505L
06.99