RL78/G1P
CHAPTER 12 SERIAL INTERFACE IICA
R01UH0895EJ0100 Rev.1.00
547
Nov 29, 2019
Figure 12-33. Example of Slave to Master Communication
(8-Clock and 9-Clock Wait Is Selected for Master, 9-Clock Wait Is Selected for Slave) (3/3)
(3) Data ~ data ~ stop condition
IICAn
STTn
(ST trigger)
SPTn
(SP trigger)
ACKDn
(ACK detection)
WTIMn
(8 or 9 clock wait)
ACKEn
(ACK control)
MSTSn
(communication status)
TRCn
(transmit/receive)
SCLAn (bus)
(clock line)
WRELn
(wait cancellation)
INTIICAn
(interrupt)
SDAAn (bus)
(data line)
IICAn
STDn
(ST detection)
SPDn
(SP detection)
ACKDn
(ACK detection)
WTIMn
(8 or 9 clock wait)
ACKEn
(ACK control)
MSTSn
(communication
status)
TRCn
(transmit/receive)
WRELn
(wait cancellation)
INTIICAn
(interrupt)
D
15
0
Master side
Bus line
Slave side
H
L
H
L
L
L
ACK
NACK
D
16
7 D
16
6 D
16
5 D
16
4 D
16
3 D
16
2 D
16
1 D
16
0
Stop condition
Note 1
Note 1
Note 3
Note 2
Notes 1, 4
Note 4
<14>
<9>
<8> <11>
<10>
<12>
<13> <16>
<19>
<15>
<17>
<18>
: Wait state by master device
: Wait state by slave device
: Wait state by master and slave devices
Notes 1.
To cancel a wait state, write “FFH” to IICAn or set the WRELn bit.
2.
Make sure that the time between the rise of the SCLAn pin signal and the generation of the stop
condition after a stop condition has been issued is at least 4.0
s when specifying standard mode and at
least 0.6
s when specifying fast mode.
3.
Write data to IICAn, not setting the WRELn bit, in order to cancel a wait state during transmission by a
slave device.
4.
If a wait state during transmission by a slave device is canceled by setting the WRELn bit, the TRCn bit
will be cleared.
Remark
n = 0, 1