During master transmit/master receive operations, even though I'm transmitting with a single master, occasionally, the IIC bus will switch to slave receive mode, stopping transmission. What could be causing this?
Even during single master transmission, sometimes data indiscrepancies cause loss of arbitration on the IIC bus line. This is especially likely to occur if there is noise, etc. affecting the SDA line. When arbitration is lost, depending on the noise waveform, the data indiscrepancy may be mistakenly recognized as a start or stop condition. Therefore, please plan IIC bus line wiring lengths and board layouts to minimize noise effects as well as prepare return processing and so on by software even for single master transmission. Note in particular that when loss of arbitration occurs during single master transmission, master rights will be lost regardless of bus free state (both SCL and SDA levels are high). In addition, for how to clear the bus busy flag (BBSY) when it has become 1 regardless of bus free state, refer to FAQ No.107070 or FAQ No.107073. The clearing condition differs by product.
|H8S/2630, 2639, 2638, 2636, 2635|
|H8S/2556, 2552, 2506|
|H8S/2472, 2463, 2462|
|H8S/2258, 2239, 2238, 2237, 2227|