RX610 Group
22. I
2
C Bus Interface (RIIC)
R01UH0032EJ0120 Rev.1.20
Page 741 of 1006
Feb 20, 2013
22.3.6
Slave Receiver Operation
In slave receiver operation, the master device outputs the SCL clock and data, and the RIIC returns acknowledgements as
a slave device.
Figure 22.17 shows an example of usage of slave reception and figures 22.18 and 22.19 show the timing of operations in
slave reception.
The following describes the procedure and operations for slave reception.
1. Follow the procedure in figure 22.5 to make initial settings for the RIIC. This step is not necessary if initialization of
the RIIC has already been completed. After initial settings, the RIIC will stay in the standby state until it receives a
slave address that it matches.
2. After receiving a matching slave address, the RIIC sets one of the corresponding bits ICSR1.HOA, GCA, and AASy
(y = 0 to 2) to 1 on the rising edge of the ninth cycle of SCL clock (the clock signal) and outputs the value set in the
ICMR3.ACKBT bit to the acknowledge bit on the ninth cycle of SCL clock. If the value of the R/W# bit that was also
received at this time is 1, the RIIC continues to place itself in slave receiver mode and sets the RDRF flag in ICSR2
to 1.
3. After the ICSR2.STOP flag is confirmed to be 0 and the ICSR2.RDRF flag to be 1, dummy read ICDRR (the dummy
value consists of the slave address and R/W# bit when the 7-bit address format is selected, or the lower eight bits
when the 10-bit address format is selected).
4. When ICDRR is read, the RIIC automatically clears the ICSR2.RDRF flag to 0. If reading of ICDRR is delayed and a
next byte is received while the RDRF flag is still set to 1, the RIIC holds the SCLn line low from one SCL cycle
before the timing with which RDRF should be set. In this case, reading ICDRR releases the SCLn line from being
held at the low level.
When the ICSR2.STOP flag is 1 and the ICSR2.RDRF flag is also 1, read ICDRR until all the data is completely
received.
5. Upon detecting the stop condition, the RIIC automatically clears bits ICSR1.HOA, GCA, and AASy (y = 0 to 2) to 0.
6. After checking that the ICSR2.STOP flag is 1, clear the ICSR2. STOP flag to 0 for the next transfer operation.
Summary of Contents for RX600 Series
Page 1006: ...RX610 Group R01UH0032EJ0120 ...