Renesas rl78 User Manual
RL78/G1A
CHAPTER 13 SERIAL INTERFACE IICA
Figure 13-29. Master Operation in Multi-Master System (2/4)
No
STT0 = 1
Wait
Slave operation
Yes
MSTS0 = 1?
EXC0 = 1 or COI0 =1?
Prepares for starting communication
(generates a start condition).
(generates a start condition).
Secure wait time
Note
by software.
Waits for bus release
(communication being reserved).
(communication being reserved).
Wait state after stop condition
was detected and start condition
was generated by the communication
reservation function.
was detected and start condition
was generated by the communication
reservation function.
No
INTIICA0
interrupt occurs?
Yes
Yes
No
A
C
Enables reserving communication.
Communication processing
Note The wait time (number of clocks of f
MCK
) is calculated as follows.
<R>
(IICWL0 setting value + IICWH0 setting value + 4) + t
F
× 2 × f
MCK
[clocks]
Remark IICWL0: IICA low-level width setting register 0
IICWH0:
IICA
high-level
width setting register 0
t
F
:
SDAA0 and SCLA0 signal falling times
f
MCK
:
IICA operation clock frequency
Figure 13-29. Master Operation in Multi-Master System (3/4)
Yes
No
No
Yes
Yes
No
Yes
No
B
D
C
D
STT0 = 1
Wait
Note
Slave operation
IICBSY0 = 0?
EXC0 = 1 or COI0 =1?
Prepares for starting communication
(generates a start condition).
(generates a start condition).
Disables reserving communication.
Waits for bus release
Detects a stop condition.
INTIICA0
interrupt occurs?
STCF0 = 0?
Communication processing
Note Wait: Wait for five clocks of f
MCL
<R>
R01UH0305EJ0200 Rev.2.00
612
Jul 04, 2013