NEC 78K0 Series User Manual page 445

Figure 17-24. Master Operation Flowchart (Multi-Master System) (3/3)
C
Writing IIC0
INTIIC0
interrupt occurs?
Yes
MSTS0 = 1?
Yes
No
ACKD0 = 1?
Yes
TRC0 = 1?
Yes
WTIM0 = 1
Writing IIC0
INTIIC0
interrupt occurs?
Yes
MSTS0 = 1?
Yes
ACKD0 = 1?
Yes
No
Transfer end?
Yes
Restart?
Yes
STT0 = 1
C
2
EXC0 = 1 or COI0 = 1?
Yes
Slave operation
Remarks 1. Conform to the specifications of the product that is communicating, with respect to the transmission
and reception formats.
2. To use the device as a master in a multi-master system, read the MSTS0 bit each time interrupt
INTIIC0 has occurred to check the arbitration result.
3. To use the device as a slave in a multi-master system, check the status by using the IICS0 and IICF0
registers each time interrupt INTIIC0 has occurred, and determine the processing to be performed
next.
CHAPTER 17 SERIAL INTERFACE IIC0
Starts communication
(specifies an address and transfer direction).
No
Waits for detection of ACK.
No
2
No
Starts transmission.
No
Waits for data transmission.
No
2
No
No
SPT0 = 1
END
No
1
Does not participate
in communication.
Preliminary User's Manual U17260EJ3V1UD
ACKE0 = 1
WTIM0 = 0
WREL0 = 1
Starts reception.
INTIIC0
No
interrupt occurs?
Waits for data reception.
Yes
No
MSTS0 = 1?
Yes
Reading IIC0
No
Transfer end?
Yes
WTIM0 = WREL0 = 1
ACKE0 = 0
INTIIC0
No
interrupt occurs?
Waits for detection of ACK.
Yes
No
MSTS0 = 1?
Yes
2
2
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