Siemens EF 88H Series Manual de usuario descargar pdf (Pagina 51)

Semiconductor Group 5 - 16

On-Chip Peripheral Components

Figure 5-5 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 the SAB 80C517. 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 the SAB 80C517.

Figure 5-5

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:

with S0REL = S0RELH.1 – 0, S0RELL.7 – 0

Mode 1, 3 baud rate =

SMOD

x oscillator frequency

64 x (2

– S0REL)

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Siemens EF 88H Series Manual de usuario Pagina 51