CHAPTER 11 SERIAL INTERFACE FUNCTION
User’s Manual U15109EJ3V0UD
395
Figure 11-30. Wait Signal (2/2)
(2) When master and slave devices both have a nine-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 and slave both wait
after output of ninth clock.
IICn data write (cancel wait)
Slave
FFH is written to IICn or WRELn is set to 1.
Output according to previously set ACKEn value
Transfer lines
Remarks 1.
ACKEn: Bit 2 of IIC control register n (IICCn)
WRELn: Bit 5 of IIC control register n (IICCn)
2.
n = 0, 1
A wait may be automatically generated depending on the setting of bit 3 (WTIMn) of IIC control register n (IICCn)
(n = 0, 1).
Normally, when bit 5 (WRELn) of IICCn is set to 1 or when FFH is written to IIC shift register n (IICn) on the
receiving side, the wait status is canceled and the transmitting side writes data to IICn to cancel the wait status.
The master device can also cancel the wait status via either of the following methods.
•
By setting bit 1 (STTn) of IICCn to 1
•
By setting bit 0 (SPTn) of IICCn to 1