RL78/G1P
CHAPTER 12 SERIAL INTERFACE IICA
R01UH0895EJ0100 Rev.1.00
509
Nov 29, 2019
Figure 12-29. Master Operation in Multi-Master System (2/3)
STTn = 1
Wait
Slave operation
Yes
MSTSn = 1?
EXCn = 1 or COIn = 1?
Prepares for starting communication
(generates a start condition).
Secure wait time
Note
by software.
Waits for bus release
(communication being reserved).
Wait state after stop condition
was detected and start condition
was generated by the communication
reservation function.
No
INTIICAn
interrupt occurs?
Yes
Yes
No
No
A
C
STTn = 1
Wait
Note
Slave operation
Yes
IICBSYn = 0?
EXCn = 1 or COIn = 1?
Prepares for starting communication
(generates a start condition).
Disables reserving communication.
Enables reserving communication.
Waits for bus release
Detects a stop condition.
No
No
INTIICAn
interrupt occurs?
Yes
Yes
No
Yes
STCFn = 0?
No
B
D
C
D
Communication processing
Communication processing
Note
The wait time is calculated as follows.
(IICWLn setting value + IICWHn setting value + 4)
f
CLK
+ t
F
2 [clocks]
Remarks 1.
IICWLn:
IICA
low-level
width setting register n
IICWHn:
IICA
high-level
width setting register n
t
F
:
SDAAn and SCLAn signal falling times
f
CLK
:
CPU/peripheral hardware clock frequency
2.
n = 0, 1