324
CHAPTER 17 SERIAL INTERFACE IIC0 (
µ
PD780344Y, 780354Y SUBSERIES ONLY)
User’s Manual U15798EJ2V0UD
17.5.6 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 SCL0 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.
Figure 17-14. Wait Signal (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)
SCL0
6
SDA0
7
8
9
1
2
3
SCL0
IIC0
6
H
7
8
1
2
3
D2
D1
D0
ACK
D7
D6
D5
9
IIC0
SCL0
ACKE0
Master
Master returns to high
impedance but slave
is in wait state (low level).
Wait after output
of ninth clock
IIC0 data write (cancel wait)
Slave
Wait after output
of eighth clock
FFH is written to IIC0 or WREL0 is set to 1
Transfer lines
Wait signal
from slave
Wait signal
from master
Содержание mPD780344 Series
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