M38203M4 Datasheet, PDF (191/344 Pages) Mitsubishi Electric Semiconductor – 8-BIT SINGLE-CHIP MICROCOMPUTER

APPLICATION
2.5 Serial I/O1
sData transfer rate (baud rate)
When an internal clock is used, the data transfer rate (baud rate), which is a shift clock frequency in
the clock synchronous mode, is determined by baud rate generator (BRG). When the BRG count
source selection bit (bit 0) of the serial I/O1 control register (address 001A16) is “0,” XIN pin input
clock is input to the BRG, when this bit is “1,” XIN pin input clock divided by 4 is input to the BRG.
The expression for baud rate is shown below.
qWhen selecting an internal clock (Using BRG)
Baud rate =
XIN pin input
[bps]
Division ratio ^V1 ! (BRG setting value ^V2 + 1) ! 4
V1 Division ratio; Select “1,” or “4”
V2 BRG setting value; 0 to 255 (0016 to FF16)
qWhen selecting an external clock
Baud rate = Frequency of input clock to P46/SCLK1 pin
[bps]
3820 GROUP USER’S MANUAL
2–105