Datasheet
RL78/L12    CHAPTER 6 TIMER ARRAY UNIT 
R01UH0330EJ0200 Rev.2.00      235 
Dec 13, 2013 
Figure 6-48. Operation Procedure of Interval Timer/Square Wave Output Function (1/2) 
 Software Operation  Hardware Status 
TAU 
default 
setting 
 Power-off status 
(Clock supply is stopped and writing to each register is 
disabled.) 
Sets the TAU0EN bit of peripheral enable register 0 
(PER0) to 1. 
Power-on status. Each channel stops operating. 
(Clock supply is started and writing to each register is 
enabled.) 
Sets timer clock select register m (TPSm). 
Determines clock frequencies of CKm0 to CKm3. 
Channel 
default 
setting 
Sets timer mode register mn (TMRmn) (determines 
operation mode of channel). 
Sets interval (period) value to timer data register mn 
(TDRmn). 
Channel stops operating. 
(Clock is supplied and some power is consumed.) 
To use the TOmn output 
Clears the TOMmn bit of timer output mode register m 
(TOMm) to 0 (master channel output mode). 
Clears the TOLmn bit to 0. 
Sets the TOmn bit and determines default level of the 
TOmn output. 
Sets the TOEmn bit to 1 and enables operation of TOmn.
Clears the port register and port mode register to 0. 
The TOmn pin goes into Hi-Z output state. 
The TOmn default setting level is output when the port mode 
register is in the output mode and the port register is 0. 
TOmn does not change because channel stops operating. 
The TOmn pin outputs the TOmn set level. 
Operation 
start 
(Sets the TOEmn bit to 1 only if using TOmn output and 
resuming operation.). 
Sets the TSmn (TSHm1, TSHm3) bit to 1. 
The TSmn (TSHm1, TSHm3) bit automatically returns 
to 0 because it is a trigger bit. 
TEmn (TEHm1, TEHm3) = 1, and count operation starts. 
Value of the TDRmn register is loaded to timer count 
register mn (TCRmn) at the count clock input. INTTMmn is 
generated and TOmn performs toggle operation if the 
MDmn0 bit of the TMRmn register is 1. 
During 
operation 
Set values of the TMRmn register, TOMmn, and TOLmn 
bits cannot be changed. 
Set value of the TDRmn register can be changed. 
The TCRmn register can always be read. 
The TSRmn register is not used. 
Set values of the TOm and TOEm registers can be 
changed. 
Counter (TCRmn) counts down. When count value reaches 
0000H, the value of the TDRmn register is loaded to the 
TCRmn register again and the count operation is continued. 
By detecting TCRmn = 0000H, INTTMmn is generated and 
TOmn performs toggle operation. 
After that, the above operation is repeated. 
Operation 
stop 
The TTmn (TTHm1, TTHm3) bit is set to 1. 
The TTmn (TTHm1, TTHm3) bit automatically returns 
to 0 because it is a trigger bit. 
TEmn (TEHm1, TEHm3), and count operation stops. 
The TCRmn register holds count value and stops. 
The TOmn output is not initialized but holds current status.
The TOEmn bit is cleared to 0 and value is set to the TOmn bit. 
The TOmn pin outputs the TOmn bit set level. 
(Remark is listed on the next page.) 
Operation is resumed. 










