Datasheet
RL78/L12    CHAPTER 12 SERIAL ARRAY UNIT 
R01UH0330EJ0200 Rev.2.00      458 
Dec 13, 2013 
(1) Register setting 
Figure 12-61. Example of Contents of Registers for Slave Transmission/Reception of 3-Wire Serial I/O 
(CSI00, CSI01) (1/2) 
(a)  Serial mode register mn (SMRmn) 
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0   
SMRmn 
CKSmn 
0/1 
CCSmn 
1 
0 
0 
0
0 
0 
STSmn
0 
0 
SISmn0
0 
1 
0 
0 
0 
MDmn1 
0 
MDmn0
0/1
Operation clock (fMCK) of channel n 
0: Prescaler output clock CKm0 set by the SPSm register 
1: Prescaler output clock CKm1 set by the SPSm register 
Interrupt source of channel n
0: Transfer end interrupt
1: Buffer empty interrupt
(b)  Serial communication operation setting register mn (SCRmn) 
  15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0   
SCRmn 
TXEmn 
1 
RXEmn 
1 
DAPmn
0/1
CKPmn 
0/1 
0
EOCmn
0 
PTCmn1
0 
PTCmn0
0 
DIRmn
0/1
0 
SLCmn1
0 
SLCmn0
0 
0 
1 
DLSmn1
1 
DLSmn0
0/1
Selection of data transfer sequence  
0: Inputs/outputs data with MSB first 
1: Inputs/outputs data with LSB first. 
Setting of data length
0: 7-bit data length
1: 8-bit data length 
Selection of the data and clock 
phase (For details about the 
setting, see 12.3 Registers 
Controlling Serial Array Unit.)
(c)  Serial data register mn (SDRmn) (lower 8 bits: SIOp) 
  15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0   
SDRmn 
0000000 
Baud rate setting 
0 
Transmit data setting/receive data register 
(d)  Serial output register m (SOm) … Sets only the bits of the target channel. 
  15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0   
SOm 
0 
0 
0 
0 
1 
1 
CKOm1
× 
CKOm0
× 
0 
0 
0 
0 
1 
1 
SOm1 
0/1 
SOm0
0/1
Caution  Be sure to set transmit data to the SlOp register before the clock from the master is started. 
Remarks 1. m: Unit number (m = 0), n: Channel number (n = 0, 1), p: CSI number (p = 00, 01), mn = 00, 01 
 2.  : Setting is fixed in the CSI slave transmission/reception mode, 
 : Setting disabled (set to the initial value) 
×: Bit that cannot be used in this mode (set to the initial value when not used in any mode) 
0/1: Set to 0 or 1 depending on the usage of the user 
SIOp 










