Renesas rl78 User Manual
RL78/G1A
CHAPTER 12 SERIAL ARRAY UNIT
R01UH0305EJ0200 Rev.2.00
530
Jul 04, 2013
12.6.4 Calculating baud rate
(1) Baud rate calculation expression
The baud rate for UART (UART0 to UART2) 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, 1), n: Channel number (n = 0 to 3), mn = 00 to 03, 10, 11
The operation clock (f
MCK
) is determined by serial clock select register m (SPSm) and bit 15 (CKSmn) of serial
mode register mn (SMRmn).