DDR memory hanging issue in K70 tower board

[pramodk_g_]

Hi all,

                                         l am using the DDR memory of twr module for storing my high speed acquisition data. Currently  I am building my project as SRAM debug and DDR is enable when necessary. So i have two functions to enable and disable DDR ( code attached below ) . Now i can enable and disable DDR at run time, but my issue is that ddr gets hang after doing some number of these enabling and disabling. Please let me know some where i went wrong. I am attaching my the functions to enabling and disabling the ddr.

Thanks,

Pramod.

/*FUNCTION*---------------------------------------------------------------------

*

* Function Name    : ddr_enable

* Returned Value   :

* Comments         : DDRAM Enabling routine.

*

*END*-------------------------------------------------------------------------*/

void ddr_enable(void)

{

    SIM_MemMapPtr   sim = SIM_BASE_PTR;

    DDR_MemMapPtr   ddr = DDR_BASE_PTR;

    MCM_MemMapPtr   mcm = MCM_BASE_PTR;

    /* Enable DDR controller clock */

    sim->SCGC3 |= SIM_SCGC3_DDR_MASK;

    /* Enable DDR pads and set slew rate */

    sim->MCR |= 0xC4;   /* bits were left out of the manual so there isn't a macro right now */

    ddr->RCR |= DDR_RCR_RST_MASK;

    * (vuint_32 *)(0x400Ae1ac) = 0x01030203;

    /* TC's init */

    ddr->CR00 = 0x00000400;

    ddr->CR02 = 0x02000031;

    ddr->CR03 = 0x02020506;

    ddr->CR04 = 0x06090202;

    ddr->CR05 = 0x02020302;

    ddr->CR06 = 0x02904002;

    ddr->CR07 = 0x01000303;

    ddr->CR08 = 0x05030201;

    ddr->CR09 = 0x020000c8;

    ddr->CR10 = 0x03003207;

    ddr->CR11 = 0x01000000;

    ddr->CR12 = 0x04920031;

    ddr->CR13 = 0x00000005;

    ddr->CR14 = 0x00C80002;

    ddr->CR15 = 0x00000032;

    ddr->CR16 = 0x00000001;

    ddr->CR20 = 0x00030300;

    ddr->CR21 = 0x00040232;

    ddr->CR22 = 0x00000000;

    ddr->CR23 = 0x00040302;

    ddr->CR25 = 0x0A010201;

    ddr->CR26 = 0x0101FFFF;

    ddr->CR27 = 0x01010101;

    ddr->CR28 = 0x00000003;

    ddr->CR29 = 0x00000000;

    ddr->CR30 = 0x00000001;

    ddr->CR34 = 0x02020101;

    ddr->CR36 = 0x01010201;

    ddr->CR37 = 0x00000200;

    ddr->CR38 = 0x00200000;

    ddr->CR39 = 0x01010020;

    ddr->CR40 = 0x00002000;

    ddr->CR41 = 0x01010020;

    ddr->CR42 = 0x00002000;

    ddr->CR43 = 0x01010020;

    ddr->CR44 = 0x00000000;

    ddr->CR45 = 0x03030303;

    ddr->CR46 = 0x02006401;

    ddr->CR47 = 0x01020202;

    ddr->CR48 = 0x01010064;

    ddr->CR49 = 0x00020101;

    ddr->CR50 = 0x00000064;

    ddr->CR52 = 0x02000602;

    ddr->CR53 = 0x03c80000;

    ddr->CR53 = 0x03c803c8;

    ddr->CR53 = 0x03c803c8;

    ddr->CR56 = 0x020303c8;

    ddr->CR57 = 0x01010002;

    _ASM_NOP();

    ddr->CR00 |= 0x00000001;

    while ((ddr->CR30 & 0x400) != 0x400) {

    }

    mcm->CR |= MCM_CR_DDRSIZE(1); 

}

/*FUNCTION*---------------------------------------------------------------------

*

* Function Name    : ddr_disable

* Returned Value   :

* Comments         : DDRAM Disabling routine.

*

*END*-------------------------------------------------------------------------*/

void ddr_disable(void)

{   

    SIM_MemMapPtr   sim = SIM_BASE_PTR;

    DDR_MemMapPtr   ddr = DDR_BASE_PTR;

//    ddr->RCR |= DDR_RCR_RST_MASK;

    /* Enable DDR pads and set slew rate */

    sim->MCR   &= ~0xC4;   /* bits were left out of the manual so there isn't a macro right now */

    /* Enable DDR controller clock */

    sim->SCGC3 &= ~SIM_SCGC3_DDR_MASK;

}

[RadekS]

I guess that this issue could be caused by problem with DDR2 clock.

TWR-K70F120M BSP configures incorrect DDR2 clock frequency. By default it is 120 MHz. JEDEC specifications minimum requires 125 MHz. Maximum allowed by K70 chip is 150 MHz.

I would like to recommend increase DDR2 clock to 150MHz or install MQX 4.1.0.1 patch which contains bug fix for this issue:

https://www.freescale.com/webapp/Download?colCode=FSLMQXOS_4_1_0_1_PATCH

Increasing DDR2 clock frequency will cause that work with DDR2 will be more stable (typically are problem only on heavy load).

Best Regards,
RadekS

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