SAB80C517-M16 SIEMENS [Siemens Semiconductor Group], SAB80C517-M16 Datasheet - Page 59

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

On-Chip Peripheral Components
Figure 7-11b shows a block diagram of the options available for baud rate generation of Serial
Channel 0. It is a fully compatible superset of the functionality of older SAB 80C517 steppings. The
new baud rate generator can be used in modes 1 and 3 of the Serial Channel 0. It is activated by
setting bit BD (ADCON0.7). This also starts the baud rate timer. When Timer1 shall be used for
baud rate generation, bit BD must be cleared. In any case, bit SMOD (PCON.7) selects an
additional divider by two.
The default values after reset in registers S0RELL and S0RELH provide a baud rate of 4.8 kBaud
(with SMOD = 0) or 9.6 kBaud (with SMOD = 1) at 12 MHz oscillator frequency. This guarantees
full compatibility to older steppings of the SAB 80C517.
Figure 7-11b
Block Diagram of Baud Rate Generation for Serial Interface 0
If the new baud rate generator is used the baud rate of Serial Channel 0 in Mode 1 and 3 can be
determined as follows:
SMOD
x oscillator frequency
2
Mode 1, 3 baud rate =
64 x (2
10
– S0REL)
with S0REL = S0RELH.1 – 0, S0RELL.7 – 0
Semiconductor Group
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