UPD78F1502AGK-GAK-AX Datasheet, PDF (631/1031 Pages) Renesas Technology Corp – 16-Bit Single-Chip Microcontrollers

78K0R/Lx3
CHAPTER 15 SERIAL INTERFACE IICA
(2) When communication reservation function is disabled (bit 0 (IICRSV) of IICA flag register (IICF) = 1)
When bit 1 (STT) of IICA control register 0 (IICCTL0) 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 (LREL) of IICCTL0 to 1 and saving communication)
To confirm whether the start condition was generated or request was rejected, check STCF (bit 7 of IICF). It takes
up to 5 clocks until STCF is set to 1 after setting STT = 1. Therefore, secure the time by software.
R01UH0004EJ0501 Rev.5.01
615
Jun 20, 2011