Datasheet
RL78/L12    CHAPTER 13 SERIAL INTERFACE IICA 
R01UH0330EJ0200 Rev.2.00      556 
Dec 13, 2013 
(2)  When communication reservation function is disabled (bit 0 (IICRSV) of IICA flag register 0 (IICF0) = 1) 
When bit 1 (STT0) of IICA control register 00 (IICCTL00) is set to 1 when the bus is not used in a communication 
during bus communication, this request is rejected and a start condition is not generated. The following two 
statuses are included in the status where bus is not used. 
• When arbitration results in neither master nor slave operation 
• When an extension code is received and slave operation is disabled (ACK is not returned and the bus was 
released by setting bit 6 (LREL0) of the IICCTL00 register to 1 and saving communication) 
To confirm whether the start condition was generated or request was rejected, check STCF (bit 7 of the IICF0 
register). It takes up to 5 clocks until the STCF bit is set to 1 after setting STT0 = 1. Therefore, secure the time by 
software. 










