Baud Rate Of Uart - Fujitsu MB90420/5 (A) Series Hardware Manual

MB90420/5 (A) SERIES F

12.6 Baud Rate of UART

One of the following can be selected as the UART transmitter/receiver clock.
• Dedicated baud rate generator
• Internal clock (16-bit reload timer)
• External clock (clock input to SCK pin)
n Selection of UART baud rate
The baud rate selector is shown below. One can be selected from the following three types of baud rate.
• Selection of baud rate by the dedicated baud rate generator
The UART contains a dedicated baud rate generator, and can select one from the eight types of baud rate
by the mode register (SMR0/1). The UART selects an asynchronous baud rate or clock-synchronous baud
rate by the frequency of the machine clock and the BCH and CS2 to CS0 of the mode register (SMR0/1).
• Baud rate by internal timer
The internal clock supplied from the 16-bit reload timer is used as a baud rate as is (synchronous) or is
used after division by 16 (asynchronous). The baud rate can be set freely by setting the reload value.
• Baud rate by external clock
The clock input from the clock input pin (SCK0/P02, SCK1/P05) of the UART is used as the baud rate as is
(synchronous) or is used after division by 16 (asynchronous). The baud rate can be set freely externally.
2
MC-16LX FAMILY 16-BIT MICROCONTROLLERS HARDWARE MANUAL
12-22