Datasheet
RL78/L12    CHAPTER 12 SERIAL ARRAY UNIT 
R01UH0330EJ0200 Rev.2.00      437 
Dec 13, 2013 
Figure 12-44. Flowchart of Master Transmission/Reception (in Single- Transmission/Reception Mode) 
Star
t
ing CSI communication 
Disable interrupt (MASK)
Transmission/reception 
completed? 
No 
Yes 
End of communication
Read receive data to SIOp 
(=SDRmn[7:0]) 
Writing transmit data to 
SIOp (=SDRmn[7:0]) 
When transfer end interrupt is generated, it 
moves to interrupt processing routine.
Wait for transmission/reception 
completes 
For the initial setting, refer to Figure 12-40. 
(Select transfer end interrupt)
SAU default setting
Transfer end interrupt
Read receive data then writes to storage area, update receive 
data pointer
RETI 
If there are the next data, it continues
Write STmn bit to 1
Setting 
transmission/reception data
Setting storage data and number of data for transmission/reception data 
(Storage area, Transmission data pointer, Reception data pointer, Number of 
communication data and Communication end flag are optionally set on the 
internal RAM by the software) 
Enables interrupt
Clear interrupt request flag (XXIF), reset interrupt mask (XXMK) and set 
interrupt enable (EI)
Writing to SIOp makes SOp 
and SCKp signals out 
(communication starts)
Read transmit data from storage area and write it 
to SIOp. Update transmit data pointer.
Main routine  Main routineInterrupt processing routine
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