Datasheet
RL78/L12    CHAPTER 12 SERIAL ARRAY UNIT 
R01UH0330EJ0200 Rev.2.00      502 
Dec 13, 2013 
12.6.4 Calculating baud rate 
(1)  Baud rate calculation expression 
The baud rate for UART (UART0) communication can be calculated by the following expressions. 
(Baud rate) = {Operation clock (f
MCK) frequency of target channel} ÷ (SDRmn[15:9] + 1) ÷ 2 [bps] 
Caution  Setting serial data register mn (SDRmn) SDRmn[15:9] = (0000000B, 0000001B) is prohibited. 
Remarks 1.  When UART is used, the value of SDRmn[15:9] is the value of bits 15 to 9 of the SDRmn register 
(0000010B to 1111111B) and therefore is 2 to 127. 
  2.  m: Unit number (m = 0), n: Channel number (n = 0, 1), mn = 00, 01 
The operation clock (f
MCK) is determined by serial clock select register m (SPSm) and bit 15 (CKSmn) of serial 
mode register mn (SMRmn). 










