On Fri, Mar 16, 2012 at 6:55 AM, wrote: > But how are SDRAM used? Also like SPI device? > In my device e.g. there are 2 and 2 SDRAM integrated > circuits(modues).Together 4 modules. > .( Let's call them M1,M2,M3,M4.) > M1&M3 are connected in a parallel way and having its OWN clock and M2&M4 > are > connected in a parallel way too and having its OWN clock but different > from M1&M3. > How I can say that some data should be written to a module M1 and not M2? > Is there any tutorial how SDRAM can be used in embeded systems? > Depends entirely on what kind of SDRAM you have. There are normal raw DRAM modules with which you must use an FPGA configured as a DRAM controller to use. Also, there are these: http://www.micron.com/products/dram/PSRAM-CellularRAM.html which let you access them like asynchronous SRAMs (they have a built in DRAM controller). You almost certainly have raw SDRAM modules, so you need to use a DRAM controller. You can use a CPLD or an FPGA and the free Xilinx tool has an SDRAM core generator for many chips to turn your FPGA into a DRAM controller. If those modules are part of some random device you opened up, chances are, there is some kind of controller, powerful CPU, or FPGA on there already using them. Maybe access it through one of those things? --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .