Renesas rl78 User Manual
RL78/G1A
CHAPTER 6 TIMER ARRAY UNIT
R01UH0305EJ0200 Rev.2.00
239
Jul 04, 2013
6.7 Timer Input (TImn) Control
6.7.1 TImn pin input circuit configuration
The signal input from a timer input pin passes through a noise filter and edge detector, and is then input to the timer
controller. If it is necessary to eliminate noise at the pin in question, enable its noise filter. The configuration of the input
circuit is shown below.
Figure 6-39. Iutput Circuit Configuration
Timer control
circuit
CCSmn
f
TCLK
f
MCK
TImn pin
TNFENmn
CISmn1,
CISmn0
STSmn2 to
STSmn0
Noise
filter
Edge
detection
Interrupt signal from mater channel
Tr
igger
selection
Count cloc
k
selection
6.7.2 Noise filter
If the noise filter is disabled, only synchronization is performed, based on the operating clock of channel n (f
MCK
). If the
noise filter is enabled, synchronization is performed based on the operating clock of channel n (f
MCK
), and then two-clock
match detection is performed. The following shows the waveforms of a signal after passing through a noise filter when the
noise filter is enabled and disabled.
Figure 6-40.
Waveform of Sampling Signal Input to TImn Pin When Noise Filter Is Enabled and Disabled
TImn pin
Noise filter OFF
Noise filter ON
Operation clock(f
MCK
)