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CHAPTER 16 SERIAL INTERFACE IICA
User’s Manual U19780EJ2V0UD
463
(2) When communication reservation function is disabled (bit 0 (IICRSV) of IICA flag register 0 (IICAF0) =
1)
When bit 1 (STT0) of IICA control register 0 (IICACTL0) 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 IICACTL0 to 1 and saving communication)
To confirm whether the start condition was generated or request was rejected, check STCF (bit 7 of IICAF0). It
takes up to 5 clocks until STCF is set to 1 after setting STT0 = 1. Therefore, secure the time by software.