I am facing a strange problem with MCF5328, DDR Micron MT46V16M16CY (16Mx16) & Flash SST39VF1601. All these three are BGA package. Initially I thought it is solder problem under BGA chip. But both flash & DDR do not work together. If DDR is removed, flash works fine. DDR always work good in any case. I have used 22 ohm for all signals going to DDR just next to DDR. Only address bus A(0)-A(15) is common to both chips. It goes directly from processor (through 22 ohm) to DDR & from processor through buffer (level shifter) to flash.
It might be a layout problem, but before I go for new 4-layer board, I want to make sure what other precautions I need to take.
If anybody has faced similar problem, please advice.