Datasheet
RL78/L12    CHAPTER 12 SERIAL ARRAY UNIT 
R01UH0330EJ0200 Rev.2.00      402 
Dec 13, 2013 
12.3.12 Serial output register m (SOm) 
The SOm register is a buffer register for serial output of each channel. 
The value of the SOmn bit of this register is output from the serial data output pin of channel n. 
The value of the CKOmn bit of this register is output from the serial clock output pin of channel n. 
The SOmn bit of this register can be rewritten by software only when serial output is disabled (SOEmn = 0). When 
serial output is enabled (SOEmn = 1), rewriting by software is ignored, and the value of the register can be changed only 
by a serial communication operation. 
The CKOmn bit of this register can be rewritten by software only when the channel operation is stopped (SEmn = 0).  
While channel operation is enabled (SEmn = 1), rewriting by software is ignored, and the value of the CKOmn bit can be 
changed only by a serial communication operation. 
To use the pin for serial interface as a port function pin, set the corresponding CKOmn and SOmn bits to “1”. 
The SOm register can be set by a 16-bit memory manipulation instruction. 
Reset signal generation clears the SOm register to 0F0FH. 
Figure 12-14. Format of Serial Output Register m (SOm) 
Address: F0128H, F0129H After reset: 0303H R/W 
Symbol 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 
SO0  0 0 0 0 0 0 
CKO
01
CKO
00
0 0 0 0 0 0 
SO 
01 
SO
00
CKO
mn 
Serial clock output of channel n 
0  Serial clock output value is “0”. 
1  Serial clock output value is “1”. 
SO 
mn 
Serial data output of channel n 
0  Serial data output value is “0”. 
1  Serial data output value is “1”. 
Caution  Be sure to clear bits 15 to 10 and 7 to 2 to “0”. 
Remark  m: Unit number (m = 0), n: Channel number (n = 0, 1) 










