Detection Of The General Call Address - Renesas RX100 Series User Manual

RX13T Group
24.7.2

Detection of the General Call Address

The RIIC has a facility for detecting the general call address (0000 000b + 0 (write)). This is enabled by setting the
ICSER.GCAE bit to 1.
If the address received after a start or restart condition is issued is 0000 000b + 1 (read) (start byte), the RIIC recognizes
this as the address of a slave device with an "all-zero" address but not as the general call address.
When the RIIC detects the general call address, both the ICSR1.GCA flag and the ICSR2.RDRF flag are set to 1 on the
rising edge of the ninth cycle of SCL clock. This leads to the generation of a receive data full interrupt (RXI). The value
of the GCA flag can be confirmed to recognize that the general call address has been transmitted.
Operation after detection of the general call address is the same as normal slave receive operation.
[General call address reception]
S 1 2
SCL0
SDA0
0 0
BBSY
AAS0
AAS1
AAS2
GCA
RDRF
Figure 24.27 Timing of GCA Flag Setting during Reception of General Call Address
R01UH0822EJ0100 Rev.1.00
Jul 31, 2019
3 4 5 6 7 8
0 0 0 0 0 W ACK
Receive data (7-bit address)
Read ICDRR register
(Dummy read [7-bit address])
9 1 2 3 4 5
Data (DATA 1)
General call address match (0000 000b + W)
2
24. I C-bus Interface (RIICa)
6 7 8 9 1 2
ACK
Receive data (DATA 1)
Read ICDRR register
(DATA 1)
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3 4 5
Data (DATA 2)