Datasheet

Section 17 I
2
C Bus Interface 2 (IIC2)
Rev. 3.00 Sep. 10, 2007 Page 357 of 528
REJ09B0216-0300
17.4.7 Noise Filter
The signal levels on the SCL and SDA pins are internally latched via the noise filter. Figure 17.16
shows a block diagram of the noise filter circuit.
The noise filter consists of two cascaded latches and a match detector. The SCL (or SDA) input
signal is sampled on the system clock. When both outputs of the latches match, its level is output
to other blocks by the match detector. If they do not match, the previous value is held.
C
QD
Match detector
Internal
SCL or SDA
signal
SCL or SDA
input signal
Sampling
clock
Sampling clock
System clock
cycle
Latch
Latch
C
Q
D
Figure 17.16 Block Diagram of Noise Filter
17.4.8 Example of Use
Flowcharts in respective modes that use the I
2
C bus interface are shown in figures 17.17 to 17.20.