Datasheet

Section 21 I
2
C Bus Interface 2 (IIC2)
Page 756 of 982 REJ09B0465-0300 Rev. 3.00
Sep 17, 2010
H8S/20103, H8S/20203, H8S/20223, H8S/20115, H8S/20215, H8S/20235 Group
(2) Transmit Operation
In transmit mode, transmit data is output from SDA in synchronization with the fall of the transfer
clock. The transfer clock is output when MST in ICCR1 is 1 and is input when MST is 0. For
transmit mode operation timing, see figure 21.14. The transmission procedure and operations in
transmit mode are described below.
1. Set the ICE bit in ICCR1 to 1. Set the MST and CKS3 to CKS0 bits in ICCR1 to 1 (Initial
setting).
2. Set the TRS bit in ICCR1 to select the transmit mode. Then, TDRE in ICSR is set.
3. Confirm that TDRE has been set. Then, write the transmit data to ICDRT. The data is
transferred from ICDRT to ICDRS, and TDRE is set automatically. The continuous
transmission is performed by writing data to ICDRT every time TDRE is set. When changing
from transmit mode to receive mode, clear TRS while TDRE is set to 1.
12 781 78 1
SCL
TRS
Bit 0
Data 1
Data 1
Data 2 Data 3
Data 2 Data 3
Bit 6 Bit 7 Bit 0 Bit 6 Bit 7 Bit 0
Bit 1
SDA
(Output)
TDRE
ICDRT
ICDRS
User
processing
[3] Write data
to ICDRT
[3] Write data
to ICDRT
[3] Write data
to ICDRT
[3] Write data
to ICDRT
[2] Set TRS
Figure 21.14 Transmit Mode Operation Timing