C6748 StarterWare SD Card Example

Norman Wong

Other Parts Discussed in Thread: TMS320C6748

Attached is a SD Card example fro the C6748. Most of the modified code is derived from SD Card code in AM335x StarterWare and uboot with some bits from linux. A great deal of of it is technically GPL'ed.
- Only LCDK-C6748 board is supported.
- Only C6748 processor is supported.
- SD Card supported, no MMC
- No card insertion detection.
- No card write protect protection.
- Card is assumed to be always inserted and writeable.
- Tested with 2GB and 4GB cards.
- Command line is via UART2 at 115200, 8N1.
- Debug printing is turned off. Enable by setting DEBUG_PRINT to 1 in mmc modules see the init progress. The debug print output will make a mess of the command line.
- CCS5.2.1.00018 on Windows
- XDS100 v1

2045.starterware_c6748_mmcsd.zip

over 11 years ago

0 Anouini mustapha over 10 years ago

Expert 1350 points

Hello !!

Is this code run on LCDK C6748.

Regards

0 Norman Wong over 10 years ago in reply to Anouini mustapha

Guru 26430 points

Yes. I have tested the code only on the LCDK C6748. No other board.

0 Ms Rhdi over 10 years ago in reply to Norman Wong

Prodigy 150 points

Hello !!

I build the program with no erros think you very much. I tested the program but i look for saving video into sd card how i can do this?

Think you !!

0 Norman Wong over 10 years ago in reply to Ms Rhdi

Guru 26430 points

It has been a long time since I looked at the code. I vaguely remember that I ported the code over to the C6748. I don't support it. No enhancements. I believe the original code allowed just directory listing and reading files. It did not have stubs for writing. I think you have to look at other ports of the fatfs library to see how others have hooked in that library.

0 DSPwork over 8 years ago in reply to Norman Wong

Intellectual 740 points

I could not get this example to work on my TMS320C6748 LCDK. I got failed to open dir. I reformatted the Micro SD Card on my Windows 7 machine to FAT32 and created a short test file.

I was able to quickly compile the code as is but don't understand what failed.

Any suggestions?

Thank you.

0 Lalindra Jayatilleke over 8 years ago in reply to DSPwork

TI__Mastermind 30365 points

Moving this thread to the correct forum.

0 Norman Wong over 8 years ago in reply to DSPwork

Guru 26430 points

Suggest you try a FAT16 volume with 8.3 file name. I believe the code is conditionally compiled to NOT support FAT32. The TI example uses a very old version of Chan's FatFS, R0.4b from 2007. Subsequent versions have fixes for FAT32.

0 Norman Wong over 8 years ago in reply to Lalindra Jayatilleke

Guru 26430 points

Please move this thread back to the StarterWare forum.

0 DSPwork over 8 years ago in reply to Norman Wong

Intellectual 740 points

Norman,

Thank you so much for the quick reply. I've followed your instruction and formatted the SD Card to FAT and your example worked.

Not to be greedy but by any chance, do you have an updated example?

Thank you again!

0 Norman Wong over 8 years ago in reply to DSPwork

Guru 26430 points

Sorry. I do not have an updated example. My customer just wanted proof that SD card access was possible from their custom 6748 board. The old FatFs version was sufficient. That was a few years ago. The FatFs code changed over the years. The interface has changed enough that it is not a simple replace and recompile. There is always hope that TI will offer an updated version.

0 DSPwork over 8 years ago in reply to Norman Wong

Intellectual 740 points

I replaced some of the files in your example package with the files from the latest StarterWare and update the compile flag for FAT32. It is working perfectly. Again I reformatted my SD Card on Windows7 to FAT32 and created two small text files. Your example code open/read/displayed the content of the file just fine.

Thanks again for the example.

0 Vivek Jayakrishnan over 8 years ago in reply to Ms Rhdi

Intellectual 515 points

Hi,

I am also looking to do the same thing. To be able to save videos onto SD card. Were you able to do this?

Vivek

0 DSPwork over 8 years ago in reply to Vivek Jayakrishnan

Intellectual 740 points

This is a baby step process. I am just happy to get an example working with the SD Card. With his example I can read FAT32 files and assume I can write files. I have not gone beyond that at this point.

So I don't have read/write speed performances. It is a concern that I have also since I need to write data as fast as possible.

0 DSPwork over 8 years ago in reply to DSPwork

Intellectual 740 points

Norman,

So I wanted to use the api disk_write to write RAW data but it will only allow 1 sector at time. Anything above, it returns an error. What do I need to do to increase the size? 255 sectors per write is best but anything above 1 is useless.

Any helpful pointers to make this modification would be appreciated.

Thank you.

0 Norman Wong over 8 years ago in reply to DSPwork

Guru 26430 points

I haven't dealt with TI processors for several years now. Back then I probably only tested with very small files. I no longer have access to any dev kits and cannot even retest with larger files. Sorry, I cannot help you. Good luck.

0 DSPwork over 8 years ago in reply to Norman Wong

Intellectual 740 points

Norman,

Thank you for your replies.

I really appreciated.

0 Titusrathinaraj Stalin over 8 years ago in reply to Norman Wong

TI__Guru** 116100 points

Dear Norman,
Thank you so much for supporting to our community members. Really appreciated.

Dear DSPwork,
Can you please refer to the following E2E discussion to improve the write speed.
e2e.ti.com/.../1686452

0 Avi Tal over 7 years ago in reply to DSPwork

Expert 1120 points

Hi,

It is simple to adapt the above sample for FAT32.

You mainly have to take care of multiple physical sectors per cluster (i.e. 8 physical sectors for cluster size of 4096 bytes).

This can be done in disk_read() & disk_write() functions like that:

for(i = 0; i < count; i++)
{

MMCSDReadCmdSend(card->ctrl, &buff[i*512], sector + i, 1);
}

or in MMCSDReadCmdSend & MMCSDWriteCmdSend.

Unfortunately I am unable to share the code since I am under NDA with my customer.

Good luck!

Avi Tal.

0 wook bae over 7 years ago in reply to DSPwork

Intellectual 280 points

I am experiencing the same problem you have gone through. Can you share how you solved the file write problem? I am trying to write a file on the SD card on C6748 but not successful so far. Futhermore, Card insertion is not detactable and file date is stick to at 2007. If you don't mind, can I have you code and how you handled this issues?

0 wook bae over 7 years ago in reply to DSPwork

Intellectual 280 points

Can I share the file list you changed ? do you mean what you updated the compile flag for FAT32 is that you add #define _FAT32 in ff.h? What about USE_FSINFO option? Did you change this from default 0 to 1?

Here is my code to test file write. Please let me know if this code is wrong.

// FIL fsrc;
FRESULT fr;

    WORD bw, btw;
//    char buffer[]= "Hello";
    btw = sizeof(buffer);
    printf("Size of buffer:%d\n",btw);
//    cFlag = 0;
    if(cFlag == 1)
    {
    fr = f_open(&g_sFileObject,"0:file.txt",FA_WRITE | FA_CREATE_ALWAYS);
    fr = f_write(&g_sFileObject, "Hello", 6, &bw);
    f_close(&g_sFileObject);
    cFlag = 0;
    printf("Returned BW value:%d\n",bw);
    }

0 wook bae over 7 years ago in reply to Avi Tal

Intellectual 280 points

Can I know why do you use 1 instead of count variable?
MMCSDReadCmdSend(card->ctrl, &buff[i*512], sector + i, 1);

0 Avi Tal over 7 years ago in reply to wook bae

Expert 1120 points

Hi,

If you look at the function implementation:

if (nblks > 1)
{
cmd.flags |= SD_CMDRSP_ABORT;
cmd.idx = SD_CMD(18);
}

So you can only use "1" as parameter.

There are, of course, many other issues with this code...

0 Avi Tal over 7 years ago in reply to wook bae

Expert 1120 points

Hi,
Please send me your email in private and we can share the code

0 Damon0932 over 7 years ago in reply to Norman Wong

Intellectual 280 points

Thanks for your example,but I just could read txt file ,bmp picture is filed. why? How could i read bmp picture and show it on the lcd?

Processors

Processors forum

C6748 StarterWare SD Card Example