Renesas rl78 User Manual

Page of 1004
 
RL78/G1A 
 
CHAPTER  6   TIMER  ARRAY  UNIT 
R01UH0305EJ0200  Rev.2.00 
 
 
255  
Jul 04, 2013 
Figure 6-52.  Operation Procedure When Frequency Divider Function Is Used 
 
 Software 
Operation 
Hardware 
Status 
 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.) 
TAU 
default 
setting 
Sets timer clock select register 0 (TPS0). 
Determines clock frequencies of CK00 to CK03. 
 
Sets corresponding bit of noise filter enable register 1 
(NFEN1) to 0 (OFF) or 1 (ON). 
Sets timer mode register 0n (TMR0n) (determines 
operation mode of channel and selects the detection 
edge). 
Sets interval (period) value to timer data register 00 
(TDR00). 
Channel stops operating. 
(Clock is supplied and some power is consumed.) 
Channel 
default 
setting 
Clears the TOM00 bit of timer output mode register 0 
(TOM0) to 0 (master channel output mode). 
Clears the TOL00 bit to 0. 
Sets the TO00 bit and determines default level of the 
TO00 output. 
 
Sets the TOE00 bit to 1 and enables operation of TO00. 
Clears the port register and port mode register to 0. 
The TO00 pin goes into Hi-Z output state. 
 
 
 
The TO00 default setting level is output when the port mode 
register is in output mode and the port register is 0. 
TO00 does not change because channel stops operating. 
The TO00 pin outputs the TO00 set level. 
Operation 
start 
Sets the TOE00 bit to 1 (only when operation is 
resumed). 
Sets the TS00 bit to 1. 
The TS00 bit automatically returns to 0 because it is a 
trigger bit. 
 
TE00 = 1, and count operation starts. 
Value of the TDR00 register is loaded to timer count 
register 00 (TCR00).  INTTM00 is generated and TO00 
performs toggle operation if the MD000 bit of the TMR00 
register is 1. 
During 
operation 
Set value of the TDR00 register can be changed. 
The TCR00 register can always be read. 
The TSR00 register is not used. 
Set values of the TO0 and TOE0 registers can be 
changed. 
Set values of the TMR00 register, TOM00, and TOL00 
bits cannot be changed. 
Counter (TCR00) counts down.  When count value reaches 
0000H, the value of the TDR00 register is loaded to the 
TCR00 register again, and the count operation is continued.  
By detecting TCR00 = 0000H, INTTM00 is generated and 
TO00 performs toggle operation. 
After that, the above operation is repeated. 
The TT00 bit is set to 1. 
The TT00 bit automatically returns to 0 because it is a 
trigger bit. 
TE00 = 0, and count operation stops. 
The TCR00 register holds count value and stops. 
The TO00 output is not initialized but holds current status. 
Operation 
stop 
The TOE00 bit is cleared to 0 and value is set to the TO00 bit. 
The TO00 pin outputs the TO00 set level. 
To hold the TO00 pin output level 
Clears the TO00 bit to 0 after the value to be held is 
set to the port register. 
When holding the TO00 pin output level is not  
necessary  
  Setting not required. 
 
 
The TO00 pin output level is held by port function. 
 
 
 
TAU 
stop 
The TAU0EN bit of the PER0 register is cleared to 0. 
Power-off status 
All circuits are initialized and SFR of each channel is also 
initialized. 
(The TO00 bit is cleared to 0 and the TO00 pin is set to 
port mode). 
 
Oper
ation is 
re
su
med. 
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