AnsweredAssumed Answered

PLLs settings changing on i.MX53?

Question asked by sekhar babu on Jun 9, 2014
Latest reply on Jun 11, 2014 by igorpadykov

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?