Datasheet
RL78/L12    CHAPTER 12 SERIAL ARRAY UNIT 
R01UH0330EJ0200 Rev.2.00      482 
Dec 13, 2013 
Figure 12-77. Procedure for Resuming UART Transmission 
(Essential) 
Yes 
No
Wait until stop the communication target 
or communication operation completed 
Completing master 
preparations? 
Port manipulation 
Changing setting of the SPSm register
Changing setting of the SDRmn register
Changing setting of the SMRmn 
register
Changing setting of the SOm 
register
Port manipulation 
Writing to the SSm register
Completing resumption setting
Disable data output of the target channel 
by setting a port register and a port mode 
register. 
Re-set the register to change the 
operation clock setting. 
Re-set the register to change the 
transfer baud rate setting (setting the 
transfer clock by dividing the operation 
clock (f
MCK
)). 
Re-set the register to change serial 
mode register mn (SMRmn) setting. 
Set the initial output level of the serial 
data (SOmn). 
Enable data output of the target channel 
by setting a port register and a port mode 
register. 
Set the SSmn bit of the target channel to 1 and set 
the SEmn bit to 1 (to enable operation). 
Setting is completed
Set transmit data to the SDRmn[7:0] bits (TXDq 
register) (8 bits) or the SDRmn[8:0] bits (9 bits) 
and start communication.
(Selective) 
(Selective) 
(Selective) 
Changing setting of the SOEm 
register
Set the SOEmn bit to 1 and enable 
output. 
Changing setting of the SOEm 
register
Clear the SOEmn bit to 0 and stop 
output. 
(Selective) 
Changing setting of the SCRmn 
register
Re-set the register to change the serial 
communication operation setting register 
mn (SCRmn) setting. 
Changing setting of the SOLm 
register
Re-set the register to change serial 
output level register m (SOLm) setting. 
Starting setting for resumption
(Essential) 
(Essential) 
(Essential) 
(Selective) 
(Selective) 
(Selective) 
(Selective) 
Remark If PER0 is rewritten while stopping the master transmission and the clock supply is stopped, wait until the 
transmission target stops or transmission finishes, and then perform initialization instead of restarting the 
transmission. 










