C505-2RM SIEMENS [Siemens Semiconductor Group], C505-2RM Datasheet - Page 36

• Manufacturer Part Number: C505-2RM
• Description: 8-Bit CMOS Microcontroller
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

Figure 14
Block Diagram of Baud Rate Generation for the Serial Interface
Table 9 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 9
Serial Interface - Baud Rate Dependencies
Serial Interface
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 1
Overflow
Note: The switch configuration shows the reset state.
OSC
Generator
(SRELH
SRELL)
Baud
Rate
÷
6
BD
–
0
1
–
Active Control Bits Baud Rate Calculation
ADCON0.7
0
1
Mode 2
Mode 0
(BD)
SMOD
–
X
X
0
1
Mode 1
Mode 3
can be selected
Only one mode
36
Controlled by timer 1 overflow :
(2
Controlled by baud rate generator
(2
(32
f
f
f
OSC
OSC
OSC
SCON.7
SCON.6
SMOD
SMOD
(SM0/
SM1)
/ 6
/ 32
/ 16
baud rate generator overflow rate)
f
timer 1 overflow rate) / 32
OSC
) /
÷
2
0
1
PCON.7
(SMOD)
C505A / C505CA
C505 / C505C
1997-12-01
MCS02733
Baud
Rate
Clock