Renesas RL78/G1P Hardware User Manual page 523

RL78/G1P
(2) When communication reservation function is disabled (bit 0 (IICRSVn) of IICA flag register n (IICFn) = 1)
When bit 1 (STTn) of IICA control register n0 (IICCTLn0) 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 (LRELn) of the IICCTLn0 register to 1 and saving communication)
To confirm whether the start condition was generated or request was rejected, check STCFn (bit 7 of the IICFn
register). It takes up to 5 clocks until the STCFn bit is set to 1 after setting STTn = 1. Therefore, secure the time
by software.
Remark n = 0, 1
R01UH0895EJ0100 Rev.1.00
Nov 29, 2019
CHAPTER 12 SERIAL INTERFACE IICA
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