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RL78/G1P
CHAPTER 6 TIMER ARRAY UNIT
R01UH0895EJ0100 Rev.1.00
178
Nov 29, 2019
6.7 Timer Input (TImn) Control
6.7.1 TImn input circuit configuration
A signal is input from a timer input pin, goes through a noise filter and an edge detector, and is sent to a timer controller.
Enable the noise filter for the pin in need of noise removal. The following shows the configuration of the input circuit.
Figure 6-39. Input Circuit Configuration
Noise
filter
Timer
controller
Edge
detection
f
TCLK
CCSmn
STSmn2 to
STSmn0
CISmn1,
CISmn0
TNFENmn
TImn pin
f
MCK
Interrupt signal from master channel
Co
un
t c
loc
k
se
lec
tio
n
Trigger
se
lec
tio
n
6.7.2 Noise filter
When the noise filter is disabled, the input signal is only synchronized with the operating clock (f
MCK
) for channel n. When
the noise filter is enabled, after synchronization with the operating clock (f
MCK
) for channel n, whether the signal keeps the
same value for two clock cycles is detected. The following shows differences in waveforms output from the noise filter
between when the noise filter is enabled and disabled.
Figure 6-40. Sampling Waveforms through TImn Input Pin with Noise Filter Enabled and Disabled
Operating clock (f
MCK
)
TImn pin
Noise filter disabled
Noise filter enabled
Caution The input waveforms to the TImn pin are shown to explain the operation when the noise filter is
enabled or disabled. When actually inputting waveforms, input them according to the TImn input
high-level and low-level widths listed in 27.4 AC Characteristics.
Summary of Contents for RL78/G1P
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