RL78/G1H CHAPTER 15 SERIAL INTERFACE IICA
R01UH0575EJ0120 Rev. 1.20 Page 470 of 920
Dec 22, 2016
15.5.16 Communication operations
The following shows three operation procedures with the flowchart.
(1) Master operation in single master system
The flowchart when using the RL78/G1H as the master in a single master system is shown below.
This flowchart is broadly divided into the initial settings and communication processing. Execute the initial
settings at startup. If communication with the slave is required, prepare the communication and then
execute communication processing.
(2) Master operation in multimaster system
In the I
2
C bus multimaster system, whether the bus is released or used cannot be judged by the I
2
C bus
specifications when the bus takes part in a communication. Here, when data and clock are at a high level for
a certain period (1 frame), the RL78/G1H takes part in a communication with bus released state.
This flowchart is broadly divided into the initial settings, communication waiting, and communication
processing. The processing when the RL78/G1H looses in arbitration and is specified as the slave is
omitted here, and only the processing as the master is shown. Execute the initial settings at startup to take
part in a communication. Then, wait for the communication request as the master or wait for the
specification as the slave. The actual communication is performed in the communication processing, and it
supports the transmission/reception with the slave and the arbitration with other masters.
(3) Slave operation
An example of when the RL78/G1H is used as the I
2
C bus slave is shown below.
When used as the slave, operation is started by an interrupt. Execute the initial settings at startup, then wait
for the INTIICAn interrupt occurrence (communication waiting). When an INTIICAn interrupt occurs, the
communication status is judged and its result is passed as a flag over to the main processing.
By checking the flags, necessary communication processing is performed.
Remark n = 0, 1
To Next Page
Loading...
Need help?
General
