Timer Input (Timn) Control; Timn Input Circuit Configuration; Noise Filter - Renesas RL78/G1P Hardware User Manual

RL78/G1P

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.
TImn pin

6.7.2 Noise filter

When the noise filter is disabled, the input signal is only synchronized with the operating clock (f
the noise filter is enabled, after synchronization with the operating clock (f
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
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.
R01UH0895EJ0100 Rev.1.00
Nov 29, 2019
Figure 6-39. Input Circuit Configuration
Interrupt signal from master channel
f
MCK
Noise
filter detection
TNFENmn CISmn1,
Operating clock (f )
MCK
CCSmn
Edge
STSmn2 to
CISmn0 STSmn0
MCK
CHAPTER 6 TIMER ARRAY UNIT
f
TCLK
Timer
controller
) for channel n. When
MCK
) for channel n, whether the signal keeps the
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