My design is based on i.MX53 processor. I am facing strange issue on my board.
I am using I2C-3 interface to drive 5 LED driver ICs, each IC can drive upto 15 LEDs. I have configured 210ms time between the LEDs ON/OFF. The I2C clock programmed to default, I am measuring it as 13.89KHz. I2C-1 is used for Camera and PMIC. I have modified the OBDS software to test my on board 75 LEDs.
The issue is when I execute LED test, some times the LED ON/OFF time is different from what I programmed (210ms) . On each board power cycle it is showing either 210ms or 840ms LED ON/OFF time. The I2C-3 clock is same on both conditions that is 13.89KHz. Why LED ON/OFF time is changing from 210ms to 840ms. I guess PLL settings are getting changed on each power cycle. Can somebody suggest me how to overcome this issue?