SAF-C515-L24M SIEMENS [Siemens Semiconductor Group], SAF-C515-L24M Datasheet - Page 31

• Manufacturer Part Number: SAF-C515-L24M
• Description: 8-Bit CMOS Microcontroller
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

Figure 13
Block Diagram of Baud Rate Generation for the Serial Interface
Table 6 below lists the values/formulas for the baud rate calculation of the serial interface with its
dependencies of the control bits BD and SMOD.
Table 6
Serial Interface - Baud Rate Dependencies
Serial Interface 0
Operating Modes
Mode 0 (Shift Register)
Mode 1 (8-bit UART)
Mode 3 (9-bit UART)
Mode 2 (9-bit UART)
Semiconductor Group
f
Timer
Overflow
Note: The switch configuration shows the reset state.
OSC
/2
1
÷ 39
÷ 6
BD
–
0
1
–
Active Control Bits Baud Rate Calculation
0
1
Mode
Mode
ADCON.7
(BD)
2
0
SMOD
–
X
X
0
1
Mode 1
Mode
3
Only one mode
can be selected
31
SCON.7
SCON.6
Controlled by timer 1 overflow :
(2
Controlled by system clock divider circuits :
(2
(SM0/
SM1)
f
f
f
OSC
OSC
OSC
SMOD
SMOD
/ 12
/ 64
/ 32
f
timer 1 overflow rate) / 32
OSC
) / 2496
÷ 2
0
1
PCON.7
(SMOD)
1997-08-01
MCB03206
Baud
Rate
Clock
C515