CHAPTER 17 SERIAL INTERFACE IIC0
Preliminary User’s Manual U17260EJ3V1UD
430
17.5.6 Wait
The wait is used to notify the communication partner that a device (master or slave) is preparing to transmit or
receive data (i.e., is in a wait state).
Setting the SCL0 pin to low level notifies the communication partner of the wait state. When wait state has been
canceled for both the master and slave devices, the next data transfer can begin.
Figure 17-18. Wait (1/2)
(1) When master device has a nine-clock wait and slave device has an eight-clock wait
(master transmits, slave receives, and ACKE0 = 1)
Master
IIC0
SCL0
Slave
IIC0
SCL0
ACKE0
Transfer lines
SCL0
SDA0
6
7
8
9
1
2
3
Master returns to high
impedance but slave
is in wait state (low level).
Wait after output
of ninth clock
IIC0 data write (cancel wait)
Wait after output
of eighth clock
Wait from slave
Wait from master
FFH is written to IIC0 or WREL0 is set to 1
6
7
8
9
1
2
3
D2
D1
D0
D7
D6
D5
ACK
H