Uart Baud Rates - Fujitsu MB90460 Series Hardware Manual

CHAPTER 17 UART
17.6

UART Baud Rates

One of the following can be selected as the UART transmitting/receiving block, the
block diagram show as below.
■ UART Baud Rate Selection
The baud rate selection circuit is designed as shown below. One of the following three types of baud rates
can be selected:
●
Baud rates determined using the dedicated baud rate generator
UART has an internal dedicated baud rate generator. One of eight baud rates can be selected using the
mode control register (SMR0/SMR1).
An asynchronous or synchronous baud rate is selected using the machine clock frequency by setting the
CS2 to CS0 bits of the mode control register (SMR0/SMR1).
●
Baud rates determined using the internal timer
The internal clock supplied from 16-bit reload timer 0 is used as it is (synchronous) or by dividing it by 16
(asynchronous) for the baud rate. Any baud rate can be set by setting the reload value.
●
Baud rates determined using the external clock
The clock input from the UART clock pulse input pins (P42/SCK0 and P62/SCK1) is used as it is
(synchronous) or by dividing it by 16 (asynchronous) for the baud rate. Any baud rate can be set
externally.
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