LPC3250 and init of SDRAM (MT48LC2M32B2 )

 LPC3250 and init of SDRAM (MT48LC2M32B2 )

Hello

I m trying to initialise a MT48LC2M32B2 SDRAM coming from MICRON with a LPC3250.
Here is my function:

void initSDRAM()
{
    int dummy = dummy;

                SDRAMCLK_CTRL = 0x0;      //validation SDRAM HCLK

                MPMCAHBControl0 = 0x1;
                MPMCAHBControl2 = 0x1;
                MPMCAHBControl3 = 0x1;
                MPMCAHBControl4 = 0x1;

                MPMCAHBTimeout0 = 0x0100;
                MPMCAHBTimeout2 = 0x0190;
                MPMCAHBTimeout3 = 0x0190;
                MPMCAHBTimeout4 = 0x0190;

            SDRAMCLK_CTRL = 0x72800;      //slow slewrate for 2V8 IO and 2.5ns delay
                MPMCControl     =  0x1;       // validation EMC
                MPMCConfig  = 0x0;        // little endian mode
                MPMCDynamicConfig0 = 0x00004300; // 64MB, 2Mbx32, 4 banks, row=11, column=8
                MPMCDynamicRasCas0 = 0x00000303; // Default setting, RAS latency 3 CCLKs, CAS latenty 3 CCLKs.
                MPMCDynamicReadConfig = 0x11;    // Command delayed strategy

                MPMCDynamicRP     = 2;          // command period: 3(n+1) clock cycles
                MPMCDynamicRAS    = 3;          // RAS command period: 4(n+1) clock cycles
                MPMCDynamicSREX   = 7;          // Self-refresh period: 8(n+1) clock cycles
        MPMCDynamicWR     = 1;          // Write recovery: 2(n+1) clock cycles
            MPMCDynamicRC     = 7;              // Active to Active cmd: 8(n+1) clock cycles
                MPMCDynamicRFC    = 7;          // Auto-refresh: 8(n+1) clock cycles
                MPMCDynamicXSR    = 7;          // Exit self-refresh: 8(n+1) clock cycles
            MPMCDynamicRRD    = 1;              // Active bank A->B: 2(n+1) clock cycles          //ini : 2
                MPMCDynamicMRD    = 2;          // Load Mode to Active cmd: 3(n+1) clock cycles
                MPMCDynamicCDLR   = 1;
        MPMCDynamicRefresh = 50;        //50 x 16CCLKs=800CCLK=7us between SDRAM refresh cycles

                wait(1);
                //envoi d'un NOP
                MPMCDynamicControl = 0x00000193;
        wait(20);  //delai de 100us mini
        // envoi d'un PRECHARGE
        MPMCDynamicControl = 0x00000113;
                MPMCDynamicRefresh = 8;
                wait(1);
                MPMCDynamicRefresh = 50;        //50 x 16CCLKs=800CCLK=7us between SDRAM refresh cycles
                wait(1);
                MPMCDynamicControl = 0x00000093;
                // envoi de la commande de programmation du MODE REGISTER
                dummy = *((volatile int *)(SDRAM_BASE_ADDR | (0x33 << 12)));
                //send NOP
        MPMCDynamicControl = 0x00000193;
                // Send command: NORMAL
                MPMCDynamicControl = 0x00000001;  //0x01 because code is in NOR FLASH
                wait(20);     //         1 = 10 us
 }

After this was executed, I can see the refresh of the SDRAM. But unfortunately, when I write something, I can t read it, even if in the debugger.
The frequency of the HCLK is 104 MHz, the same as the EMC clk.
Can someone help me with this problem?
Thanks in advance

Best Regards
Yuga

 RE: LPC3250 and init of SDRAM (MT48LC2M32B2 )

I suggest you take a look at example for Phytec board for reference, it can be found in folder:
\ARM\Boards\Phytec\LPC3250\Blinky\

 RE: LPC3250 and init of SDRAM (MT48LC2M32B2 )

I do. The code I write come from the Phytec example. On the evaluation board, the code for the initialization SDRAM and my code for test works great (but it s not the same size and voltage of SDRAM). When I change the parameters for my SDRAM, there is any response of it. Therefore I post here.

Thanks in advance
Yuga

 RE: LPC3250 and init of SDRAM (MT48LC2M32B2 )

There is no simple solution to your problem, you have to analyze datasheet for memory that you are using and implement manufacturers initialization routine exactly.
Usually the problem is in delays needed in initialization routine perhaps they are not as requested by manufacturer.
Also you can try to find some source code for initializing these chips and analyze it.

 RE: LPC3250 and init of SDRAM (MT48LC2M32B2 )

Hi,

I am trying to interface similar sdram, MT48LC4M16A2 to LPC3240 and facing same problem. Please let me know if you were able to solve the problem.