We use AM1808BZWTD4 with one DDR2 device,16bit, without terminators.
The am1808 is running at 432M Hz,and ddr2 is running at 144M Hz
If we use normal drive strength, the system can work normally, but the overshoot is above the specification.
If we use weak drive strength, the system will crash sometimes, after crashed, we use the JTAG to read the DDR2 data, the data is wrong, then we reset the ddr controller, the data reading from ddr is right. So, we think the ddr contoller is down. When we use weak drive strength, the signal interality is good.
The schematic and the PCB design is follow the datasheet, and we check the power of 1.8V, it is normal.