Renesas RL78/G1P Hardware User Manual page 510

RL78/G1P
12.5.6 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 SCLAn 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.
(1) When master device has a nine-clock wait and slave device has an eight-clock wait
(master transmits, slave receives, and ACKEn = 1)
Master
Slave
Transfer lines
Remark n = 0, 1
R01UH0895EJ0100 Rev.1.00
Nov 29, 2019
Figure 12-20. Wait (1/2)
Master returns to high
impedance but slave
is in wait state (low level).
IICAn
SCLAn 6 7
Wait after output
of eighth clock
IICAn
SCLAn
H
ACKEn
6 7
SCLAn
SDAAn D2 D1
CHAPTER 12 SERIAL INTERFACE IICA
Wait after output
of ninth clock
8 9
FFH is written to IICAn or WRELn is set to 1
Wait from slave Wait from master
8 9
D0 ACK
IICA0 data write (cancel wait)
1 2 3
1 2 3
D7 D6 D5
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