MK70 DDR2 Clock running @120MHz

[vinodkaduppadi]

HI

I have a MK70 board which is designed by us with Micron DDR2 been in production for some time and we are getting a higher number of fallouts ( 10%) from production . when we investigated it the problem seems like while booting the LCD  shows the bootloader version and all then suddenly the board goes blank until next powercycle , when we probed the DDR2 clock it  shows 120MHz instead of 150MHz which we have configured for , the DDR2 clock always @ 120Mhz even during the LCD screen is present , any clues /suggetions to try with .

Thanks

Vinod

[Kan_Li]

Hi Vinod,

There are two clock inputs for DDRMC module, one is HCLK, the other is CLK/CLK2x, CLK/CLK2X is always sourced by PLL1 in the MCG, and HCLK source is selectable (PLL0 or PLL1 with MCG_C11[PLLCS] ), When HCLK source is PLL1 ( both clocks are the same ) the DDRMC will run in SYNCHRONOUS Mode, Else it will run in ASYNCRONOUS Mode, so would you please help to clarify which mode DDRMC was running on your board? and how did you configure the PLL1 and PLL0? Thanks for your patience!

Have a great day,
Kan