RX610 Group
22. I
2
C Bus Interface (RIIC)
R01UH0032EJ0120 Rev.1.20
Page 752 of 1006
Feb 20, 2013
22.7.4
Host Address Detection
The RIIC has a function to detect the host address while the SMBus is operating. When the HOAE bit in ICSER is set to
1 while the SMBS bit in ICMR3 is 1, the RIIC can detect the host address (0001 000b) in slave receive mode (MST and
TRS bits = 00b in ICCR2).
When the RIIC detects the host address, the HOA flag in ICSR1 is set to 1 at the falling edge of the ninth SCL clock
cycle, and at the same time, the TDRE flag in ICSR2 is set to 1 when the R/W# bit is 0 (Wr bit). This causes a transmit
data empty interrupt (ICTXI) to be generated. The HOA flag is used to recognize that the host address was sent from the
smart battery or other devices.
If the bit following the host address (0001 000b) is an Rd bit (R/W# bit = 1), the RIIC can also detect the host address.
After the host address is detected, the RIIC operates in the same manner as normal slave operation.
Read ICDRR
(Dummy read [7-bit address])
AAS2
AAS0
S
1
AAS1
9
ACK
BBSY
RDRF
2
3
4
5
6
7
8
9
ACK
1
[Host address reception]
1
0
HOA
2
3
4
5
6
7
0
0
1
0
0
0
SCLn
SDAn
8
W
2
3
4
5
Data (DATA1)
Data (DATA2)
Read ICDRR
(DATA1)
Receive data (7-bit address)
Receive data (DATA1)
Host address match (0001 000b)
Figure 22.28 HOA Flag Set Timing during Reception of Host Address
Summary of Contents for RX600 Series
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