I am developing new device.
At this time I have 8 samples of soldered board.
Each board has SSM2603 audio codec.
In two boards codec doesn't respond on I2C line at minus 30 degree.
I am using software I2C at BF533 DSP.
At normal conditions I2C works 100% well.
I decreased SCLK of I2C from 250 kHz to 60 kHz but it has not affect at low temp.
At normal conditions and at high temp +55 all boards works fine.
BF533 has logs on UART at 500 kbit/sec and DSP works fine.
Where I have to search problem?