How to use 128M DDR SDRAM on C6748 LCDK?

Jason,

DDR2 on LCDK starts at 0xc0000000 so if you modify your linker command file to following, you should be able to use 128MB on the LCDK.

DDR2:   org  = 0xC0000000        len = 0x08000000.

The generated linker.cmd file comes from platform definition of evmOMAPL138 or evmC6748 from the XDC package that you can find in the platform.tci or platform.xdc file under path xdctools_3_2x_xx_xx\packages\ti\platforms\evmOMAPL138. you can change the definition of DDR there to incorporate it in your project or create your own platfrom definition.

You can create your own platform definition as shown in the RTSC platform wizard demo shown here:

http://rtsc.eclipse.org/docs-tip/Demo_of_the_RTSC_Platform_Wizard_in_CCSv4

Hope this helps.

Regards,

Rahul

Rahul,

Thanks a lot for your reply. I am doing the test using the facedetect demo application. Its default platform is ti.platforms.evmOMAPL138. Changing it to evmC6748 cannot generate a workable binary for my C6748 LCDK board.

And under C:\Program Files\Texas Instruments\xdctools_3_23_00_32\packages\ti\platforms\evmOMAPL138, I indeed found both Platform.xdc and Platform.tci. It's interesting that both files contain some configurations that specify the DDR starts from 0xC00000000 and has 16M length. I modified these 2 files according to your suggestion. For Platform.xdc, the changed lines are:

override readonly config xdc.platform.IPlatform.Memory
        externalMemoryMap[string] = [
            /* ["DDR",  {name: "DDR",  base: 0xC3000000, len: 0x01000000}], */
            ["DDR",  {name: "DDR",  base: 0xC000000, len: 0x8000000}],
        ];

For Platform.tci, the changed lines are:

mem_ext[0] = {
    comment: "16Mbytes of the DSP's off-chip memory",
    name: "DDR",
    /* base: 0xC3000000, */
    /* len:  0x01000000, */
    base: 0xC000000,
    len:  0x08000000,
    space: "code/data"
};

However, after a clean and rebuild, the resulting linker.cmd still has:

DDR :org = 0xc3000000, len = 0x1000000

Any suggestions?

Thanks,
Jason Geng