SAB80C517-M16 SIEMENS [Siemens Semiconductor Group], SAB80C517-M16 Datasheet - Page 57

• Manufacturer Part Number: SAB80C517-M16
• Description: 8-Bit CMOS Single-Chip Microcontroller
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

Table 7-5
Baud Rates of Serial Interface 0
Baud Rate Derived
from
Timer 1 in mode 1
(see table 7-4)
Timer 1 in mode 2
(see table 7-4)
Oscillator
BD
7.2.1.4 New Baud Rate Generator for Serial Channel 0
The SAB 80C517 devices with stepping code "CA" or later have a new baud rate generator for serial
channel 0 which provides greater flexibility and better resolution. It substitutes the 80C517’s baud
rate generator at Serial Channel 0 which provides only 4.8 kBaud or 9.6 kBaud at 12 MHz crystal
frequency. Since the new generator offers greater flexibility it is often possible to use it instead of
Timer1 which is then free for other tasks.
Figure 7-11a shows a block diagram of the new baud rate generator for Serial Channel 0. It consists
of a free running 10-bit timer with f
automatic reload from the registers S0RELL (address AA H ) and S0RELH (address BA H ). The
lower 8 bits of the timer are reloaded from S0RELL, while the upper two bits are reloaded from bit
0 and 1 of register S0RELH. The baud rate timer is reloaded by writing to S0RELL.
Semiconductor Group
Interface
Mode
1, 3
1, 3
2
1, 3
OSC
/2 input frequency. On overflow of this timer there is an
Baud Rate
2
2
2
2
SMOD
SMOD
SMOD
SMOD
2
2
2
2
58
x
x
x
x
16
16
16
16
1
1
1
1
On-Chip Peripheral Components
x
x
x
x (timer 1 overflow rate)
12 x (256 – (TH1))
f
1248
OSC
f
2
OSC
f
OSC