Datasheet

Table Of Contents
Section 22 I
2
C Bus Interface 2 (IIC2)
Rev. 2.00 Jul. 04, 2007 Page 507 of 692
REJ09B0309-0200
22.4.7 Noise Canceller
The logic levels at the SCL and SDA pins are routed through noise cancellers before being latched
internally. Figure 22.16 shows a block diagram of the noise canceller circuit.
The noise canceller consists of two cascaded latches and a match detector. The SCL (or SDA)
input signal is sampled on the system clock, but is not passed forward to the next circuit unless the
outputs of both latches agree. If they do not agree, 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
period
Latch
Latch
C
Q
D
Figure 22.16 Block Diagram of Noise Canceller
22.4.8 Example of Use
Flowcharts in respective modes that use the I
2
C bus interface are shown in figures 22.17 to 22.20.