we are designing a BF548-based system with DDR SDRAM memory.
In our application we need 128MBytes of DDR RAM and we must use two 64MBytes chips organized ad 32Mx16bit (model Micron MT46V32M16P-5BL). We planned to put one SDRAM chip on each external bank (see attached picture) connecting DQM[1:0], DQS[1:0] and DQ[15:0] gluelessly in parallel as showed. We think this is possible without any issue, but we can't find any clear example or application note showing this specific configuration. Is there any kind of problem in this setup?
Moreover in our board we use the USB peripheral in host mode only and the external device connected to the USB port is always powered by the board itself (so when power to the board is shut-down the USB device is always powered-down as well). In this configuration can we connect VDDUSB to VDDEXT (i mean without the circuit of EZ-KIT board providing supply from either 5V_USB or 3.6V)?
Thank You in advance for any help.