CHAPTER 11 SERIAL INTERFACE FUNCTION
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User’s Manual U15109EJ3V0UD
(6) Wait signal (WAIT)
The wait signal (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 SCLn pin to low level notifies the communication partner of the wait status. When the wait status has
been canceled for both the master and slave devices, the next data transfer can begin (n = 0, 1).
Figure 11-30. Wait Signal (1/2)
(1) When master device has a nine-clock wait and slave device has an eight-clock wait
(master: transmission, slave: reception, and ACKEn = 1)
SCLn
6
SDAn
7
8
9
1
2
3
SCLn
IICn
6
H
7
8
1
2
3
D2
D1
D0
ACK
D7
D6
D5
9
IICn
SCLn
ACKEn
Master
Master returns to high
impedance but slave
is in wait state (low level).
Wait after output
of ninth clock.
IICn data write (cancel wait)
Slave
Wait after output
of eighth clock.
FFH is written to IICn or WRELn is set to 1.
Transfer lines
Remark
n = 0, 1