Datasheet
RL78/L12    CHAPTER 12 SERIAL ARRAY UNIT 
R01UH0330EJ0200 Rev.2.00      503 
Dec 13, 2013 
Table 12-4. Selection of Operation Clock For UART 
SMRmn 
Register 
SPSm Register  Operation Clock (fMCK)
 Note
CKSmn PRS 
m13 
PRS 
m12 
PRS 
m11 
PRS 
m10 
PRS 
m03 
PRS
m02
PRS
m01
PRS
m00
 fCLK = 24 MHz 
0  X X X X 0 0 0 0 fCLK 24 MHz 
X X X X 0 0 0 1 fCLK/2 12 MHz 
X X X X 0 0 1 0 fCLK/2
2
 6 MHz 
X X X X 0 0 1 1 fCLK/2
3
 3 MHz 
X X X X 0 1 0 0 fCLK/2
4
 1.5 MHz 
X X X X 0 1 0 1 fCLK/2
5
 750 kHz 
X X X X 0 1 1 0 fCLK/2
6
 375 kHz 
X X X X 0 1 1 1 fCLK/2
7
 187.5 kHz 
X X X X 1 0 0 0 fCLK/2
8
 93.8 kHz 
X X X X 1 0 0 1 fCLK/2
9
 46.9 kHz 
X X X X 1 0 1 0 fCLK/2
10
 23.4 kHz 
X X X X 1 0 1 1 fCLK/2
11
 11.7 kHz 
  X X X X 1 1 0 0 fCLK/2
12
 5.86 kHz 
  X X X X 1 1 0 1 fCLK/2
13
 2.93 kHz 
  X X X X 1 1 1 0 fCLK/2
14
 1.46 kHz 
  X X X X 1 1 1 1 fCLK/2
15
 732 Hz 
1  0 0 0 0 X X X X fCLK 24 MHz 
0 0 0 1 X X X X fCLK/2 12 MHz 
0 0 1 0 X X X X fCLK/2
2
 6 MHz 
0 0 1 1 X X X X fCLK/2
3
 3 MHz 
0 1 0 0 X X X X fCLK/2
4
 1.5 MHz 
0 1 0 1 X X X X fCLK/2
5
 750 kHz 
0 1 1 0 X X X X fCLK/2
6
 375 kHz 
0 1 1 1 X X X X fCLK/2
7
 187.5 kHz 
1 0 0 0 X X X X fCLK/2
8
 93.8 kHz 
1 0 0 1 X X X X fCLK/2
9
 46.9 kHz 
1 0 1 0 X X X X fCLK/2
10
 23.4 kHz 
1 0 1 1 X X X X fCLK/2
11
 11.7 kHz 
  1 1 0 0 X X X X fCLK/2
12
 5.86 kHz 
  1 1 0 1 X X X X fCLK/2
13
 2.93 kHz 
  1 1 1 0 X X X X fCLK/2
14
 1.46 kHz 
  1 1 1 1 X X X X fCLK/2
15
 732 Hz 
Other than above  Setting prohibited 
Note  When changing the clock selected for fCLK (by changing the system clock control register (CKC) value), do so 
after having stopped (serial channel stop register m (STm) = 000FH) the operation of the serial array unit 
(SAU). 
Remarks 1.  X: Don’t care 
 2.  m: Unit number (m = 0), n: Channel number (n = 0, 1), mn = 00, 01 










