Datasheet

78K0/Ix2 CHAPTER 15 SERIAL INTERFACE IICA
R01UH0010EJ0500 Rev.5.00 495
Feb 28, 2012
15.5.2 Addresses
The address is defined by the 7 bits of data that follow the start condition.
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 the 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 the slave address register 0 (SVA0). If the address data matches the SVA0 register
values, the slave device is selected and communicates with the master device until the master device generates a start
condition or stop condition.
Figure 15-17. Address
SCLA0
SDAA0
INTIICA0
123456789
A6 A5 A4 A3 A2 A1 A0 R/W
Address
Note
Note INTIICA0 is not issued if data other than a local address or extension code is received during slave device
operation.
Addresses are output when a total of 8 bits consisting of the slave address and the transfer direction described in
15.5.3 Transfer direction specification are written to the IICA shift register (IICA). The received addresses are written
to the IICA register.
The slave address is assigned to the higher 7 bits of the IICA register.
15.5.3 Transfer directio
n specification
In addition to the 7-bit address data, the master device sends 1 bit that specifies the transfer direction.
When this transfer direction specification bit has a value of “0”, it indicates that the master device is transmitting data to
a slave device. When the transfer direction specification bit has a value of “1”, it indicates that the master device is
receiving data from a slave device.
Figure 15-18. Transfer Direction Specification
SCLA0
SDAA0
I
NTIICA0
123456789
A6 A5 A4 A3 A2 A1 A0 R/W
Transfer direction specification
Not
e
Note INTIICA0 is not issued if data other than a local address or extension code is received during slave device
operation.