Renesas RL78/G1H, User Manual

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RL78/G1H CHAPTER 7 TIMER ARRAY UNIT
R01UH0575EJ0120 Rev. 1.20 Page 179 of 920
Dec 22, 2016
(2) Operation of event counter mode
<1> Timer count register mn (TCRmn) holds its initial value while operation is stopped (TEmn = 0).
<2> Operation is enabled (TEmn = 1) by writing 1 to the TSmn bit.
<3> As soon as 1 has been written to the TSmn bit and 1 has been set to the TEmn bit, the value of timer
data register mn (TDRmn) is loaded to the TCRmn register to start counting.
<4> After that, the TCRmn register value is counted down according to the count clock of the valid edge of
the TImn input.
Figure 7 - 29 Operation Timing (In Event Counter Mode)
Remark The timing is shown in Figure 7 - 29 indicates while the noise filter is not used. By making the noise filter on-
state, the edge detection becomes 2 f
MCK
cycles (it sums up to 3 to 4 cycles) later than the normal cycle of
TImn input. The error per one period occurs be the asynchronous between the period of the TImn input and
that of the count clock (f
MCK
).
f
MCK
TSmn (Write)
TEmn
TImn input
Count clock
Start trigger
detection signal
<1>
<2>
<4>
Edge detection Edge detection
TCRmn
TDRmn
<3>
<3>
<1>
Initial value
m m - 1 m - 2
m