Renesas rl78 User Manual

 

RL78/G1A 

 

CHAPTER  13   SERIAL  INTERFACE  IICA 

The following shows three operation procedures with the flowchart. 

 

The flowchart when using the RL78/G1A 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. 

 

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/G1A 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/G1A 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. 

 

An example of when the RL78/G1A 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 

INTIICA0 interrupt occurrence (communication waiting).  When an INTIICA0 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. 

R01UH0305EJ0200  Rev.2.00 

 

 

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Jul 04, 2013