Renesas RL78/G1H, User Manual

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RL78/G1H CHAPTER 7 TIMER ARRAY UNIT
R01UH0575EJ0120 Rev. 1.20 Page 182 of 920
Dec 22, 2016
(5) Operation of capture & one-count mode (high-level width measurement)
<1> Operation is enabled (TEmn = 1) by writing 1 to the TSmn bit of timer channel start register m (TSm).
<2> Timer count register mn (TCRmn) holds the initial value until start trigger generation.
<3> Rising edge of the TImn input is detected.
<4> On start trigger detection, the value of 0000H is loaded to the TCRmn register and count starts.
<5> On detection of the falling edge of the TImn input, the value of the TCRmn register is captured to
timer data register mn (TDRmn) and INTTMmn is generated.
Figure 7 - 32 Operation Timing (In Capture & One-count Mode: High-level Width Measurement)
Remark The timing is shown in Figure 7 - 32 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
(f
TCLK
)
TSmn (Write)
TEmn
TImn input
Rising edge
Start trigger
detection signal
<1>
<2>
<4>
TCRmn
INTTMmn
<3>
Initial value 1 FFFF m 0
Edge detection
<5>
Start trigger input wait
status