RL78/G15 CHAPTER 13 SERIAL INTERFACE IICA
R01UH0959EJ0110 Rev.1.10 Page 558 of 765
Mar 7, 2023
Figure 13-28. Master Operation in Multi-master System (2/3)
INTIICA0 interrupt
occurred?
Yes
Communication processing
MSTS0
=
1
?
Yes
No
Slave operation
STT0
=
1
A
Enable communication reservation
No
Wait for bus release
(communication being reserved)
Wait
EXC0 = 1 or COI0 = 1?
Prepare for starting communication
(generate a start condition)
Secure the wait time
Note 1
by software
C
After the stop condition was detected,
the wait state is entered following the
generation of a start condition by the
communication reservation
Yes
Note 1. A wait time is as follows.
(IICWL0 setting value + IICWH0 setting value + 4)/f
CLK
+ t
F
× 2
INTIICA0 interrupt
occurred?
Yes
Communication processing
STCF0
= 0?
Yes
No
Slave operation
STT0 = 1
B
Disable communication reservation
No
Wait for bus release
Wait
EXC0 = 1 or COI0 = 1?
Prepare for starting communication
(generate a start condition)
Wait for 5 clock cycles of f
CLK
C
Yes
IICBSY0 = 0?
D
Yes
No
Detect the stop condition
No
D
Remark IICWL0: IICA low-level width setting register 0
IICWH0: IICA high-level width setting register 0
t
F
: SDAA0 and SCLA0 signal falling time
f
CLK
: CPU/peripheral hardware clock frequency