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(1)
Start condition
A start condition is met when the SCLn pin is at high level and the SDAn pin changes from high level to low
level. The start conditions for the SCLn pin and SDAn pin are signals that the master device outputs to the
slave device when starting a serial transfer. The slave device includes hardware for detecting start conditions
(n = 0, 1).
A start condition is output when IIC control register n (IICCn)'s bit 1 (STTn) is set to 1 after a stop condition has
been detected (SPDn: Bit 0 = 1 in the IIC status register n (IICSn)). When a start condition is detected, IICSn's
bit 1 (STDn) is set to 1 (n = 0, 1).
(2)
Addresses
The 7 bits of data that follow the start condition are defined as an address.
An address is a 7-bit data segment that is output in order to select one of the slave devices that are connected
to the master device via bus lines. Therefore, each slave device connected via the bus lines must have a
unique address.
The slave devices include hardware that detects the start condition and checks whether or not the 7-bit address
data matches the data values stored in slave address register n (SVAn). If the address data matches the SVAn
values, the slave device is selected and communicates with the master device until the master device transmits
a start condition or stop condition (n = 0, 1).
SCLn
SDAn
INTIICn
Note INTIICn is not generated if data other than a local address or extension code is received during slave
device operation.
Remark
n = 0, 1
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CHAPTER 10
SERIAL INTERFACE FUNCTION
Figure 10-18. Start Conditions
H
SCL
SDA
Figure 10-19. Address
1
2
3
4
AD6
AD5
AD4
AD3
AD2
Address
User's Manual U13850EJ4V0UM
5
6
7
8
9
AD1
AD0
R/W
Note
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