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RL78/G1P
CHAPTER 12 SERIAL INTERFACE IICA
R01UH0895EJ0100 Rev.1.00
492
Nov 29, 2019
Figure 12-20. Wait (2/2)
(2) When master and slave devices both have a nine-clock wait
(master transmits, slave receives, and ACKEn = 1)
Master
IICAn
SCLAn
Slave
IICAn
SCLAn
ACKEn
Transfer lines
SCLAn
SDAAn
H
6
7
8
9
1
2
3
Master and slave both wait
after output of ninth clock
Wait from
master and
slave
Wait from slave
IICAn data write (cancel wait)
FFH is written to IICAn or WRELn is set to 1
6
7
8
9
1
2
3
D2
D1
D0
ACK
D7
D6
D5
Generate according to previously set ACKEn value
Remark
ACKEn: Bit 2 of IICA control register n0 (IICCTLn0)
WRELn: Bit 5 of IICA control register n0 (IICCTLn0)
A wait may be automatically generated depending on the setting of bit 3 (WTIMn) of IICA control register n0 (IICCTLn0).
Normally, the receiving side cancels the wait state when bit 5 (WRELn) of the IICCTLn0 register is set to 1 or when
FFH is written to the IICA shift register n (IICAn), and the transmitting side cancels the wait state when data is written to
the IICAn register.
The master device can also cancel the wait state via either of the following methods.
• By setting bit 1 (STTn) of the IICCTLn0 register to 1
• By setting bit 0 (SPTn) of the IICCTLn0 register to 1
Remark
n = 0, 1
Summary of Contents for RL78/G1P
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