SH7670 Datasheet, PDF (885/1292 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7670 Series

Section 19 I²C Bus Interface 3 (IIC3)
19.4.5 Slave Receive Operation
In slave receive mode, the master device outputs the transmit clock and transmit data, and the
slave device returns an acknowledge signal. For slave receive mode operation timing, refer to
figures 19.11 and 19.12. The reception procedure and operations in slave receive mode are
described below.
1. Set the ICE bit in ICCR1 to 1. Set bits CKS[3:0] in ICCR1. (Initial setting) Set the MST and
TRS bits in ICCR1 to select slave receive mode, and wait until the slave address matches.
2. When the slave address matches in the first frame following detection of the start condition,
the slave device outputs the level specified by ACKBT in ICIER to SDA, at the rise of the 9th
clock pulse. At the same time, RDRF in ICSR is set to read ICDRR (dummy read). (Since the
read data show the slave address and R/W, it is not used.)
3. Read ICDRR every time RDRF is set. If 8th receive clock pulse falls while RDRF is 1, SCL is
fixed low until ICDRR is read. The change of the acknowledge before reading ICDRR, to be
returned to the master device, is reflected to the next transmit frame.
4. The last byte data is read by reading ICDRR.
SCL
(Master output)
9
SDA
(Master output)
SCL
(Slave output)
SDA
A
(Slave output)
RDRF
ICDRS
ICDRR
1
2
3
4
5
6
7
8
9
1
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Bit 7
A
Data 1
Data 2
Data 1
User
processing
[2] Read ICDRR (dummy read)
[2] Read ICDRR
Figure 19.11 Slave Receive Mode Operation Timing (1)
Rev. 1.00 Nov. 14, 2007 Page 859 of 1262
REJ09B0437-0100