Datasheet
Section 16 I2C Bus Interface 2 (IIC2) 
R01UH0310EJ0500 Rev. 5.00    Page 955 of 1384 
Sep 25, 2012     
H8S/2426, H8S/2426R, H8S/2424 Group 
Section 16 I
2
C Bus Interface 2 (IIC2) 
This LSI has a four-channel I
2
C bus interface. 
The I
2
C bus interface conforms to and provides a subset of the NXP I
2
C bus (inter-IC bus) 
interface functions (Rev. 0.3) for standard-mode and fast-mode. The register configuration that 
controls the I
2
C bus differs partly from the NXP configuration, however. 
Figure 16.1 shows a block diagram of the I
2
C bus interface 2. Figure 16.2 shows an example of 
I/O pin connections to external circuits. 
16.1  Features 
•  Continuous transmission/reception 
Since the shift register, transmit data register, and receive data register are independent from 
each other, the continuous transmission/reception can be performed. 
•  Start and stop conditions generated automatically in master mode 
•  Selection of acknowledge output levels when receiving 
•  Automatic loading of acknowledge bit when transmitting 
•  Bit synchronization/wait function 
In master mode, the state of SCL is monitored per bit, and the timing is synchronized 
automatically. If transmission/reception is not yet possible, set the SCL to low until 
preparations are completed. 
•  Six interrupt sources 
Transmit-data-empty (including slave-address match), transmit-end, receive-data-full 
(including slave-address match), arbitration lost, NACK detection, and stop condition 
detection 
•  Direct bus drive 
Two pins, SCL and SDA pins function as NMOS open-drain outputs. 










