topic Re: SDHC working with DMA in Kinetis Microcontrollers

SDHC working with DMA

jocelyn_massero — Thu, 29 Oct 2020 09:31:50 GMT

Hi,

I'm trying to develop a program which communicatee with WIFI card over SDIO protocol. The SDIO protocol part working fine but I want to use the simple internal DMA to read and write data. However I got at every time a DMA ERROR interrupt (the DMA TRANSFER COMPLETE flag is also fired up). Here is my configuration program:

SDIO_SetWriteWatermark(SDHC_BASE_PTR, (u32)(count&0xffff));SDIO_SetReadWatermark(SDHC_BASE_PTR, (u32)(count&0xffff));SDIO_SetDMAAddress(SDHC_BASE_PTR, (u32)data); // data is an pointer over my bufferSDIO_SetCommandArgument(SDHC_BASE_PTR, arg); SDIO_SendCommand(SDHC_BASE_PTR, SDIO_CMD53_IO_RW_EXTENDED,SDIO_ENABLE_DMA |                                                         SDIO_DATA_PRESENT |                                                         SDIO_DATA_READ |                                                        SDIO_RESPONSE_LENGTH_48);

Someone has an idea to get the SDIO working fine with the internal DMA?

Thanks,

Jocelyn

Re: SDHC working with DMA

mjbcswitzerland — Wed, 09 Nov 2011 02:23:44 GMT

Hi Jocelyn

I didn't manage to get ADMA working on the SDIO. The problem that I had was that I was getting data from the chip (visible with logic analyser) but the ADMA2 was giving an error that its buffer descriptor was invalid (DMA error).

Its buffer descriptor is very simple and I didn't see why it should report that the valid bit is not set (even if I filled the buffer descriptor with 0xffffffff 0xffffffff it reported the same error, even though no bit is a '0'...(?)). Therefore I always used it since then in non-DMA mode.

Is this a different problem to yours or is it effectively the same?

Regards

Mark

Re: SDHC working with DMA

jocelyn_massero — Wed, 09 Nov 2011 02:31:35 GMT

Thanks for your reply,

Yes I have the same error as yours when I use ADMA2. That's really weird because the descriptor seems to be correct. I also tried the simple DMA mode and I have also a DMA error.

Hope that someone will can help us.

Regards

Jocelyn

Re: SDHC working with DMA

mjbcswitzerland — Wed, 09 Nov 2011 04:43:26 GMT

Hi Jocelyn

I haven't found any examples on this so I am assuming that it doesn't work (rather than invest too much time getting no where). It would ceretainly be good if freescale could add a demonstration in this mode to know that it will be worth making the attempt to overcome difficulties, whereby I would expect that the trick to getting it working will be visible in the example.

It may be due to ADMA access rights but I didn't find what may be controlling it - in which case the actual DMA error may be misleading (eg. if the DMA controller can't actually access the buffer descriptor). In other DMA cases it sometimes occurs that there is a problem with access rights but I have otherwise always found that the DMA error made this fairly clear....

Regards

Mark

Re: SDHC working with DMA

jocelyn_massero — Wed, 16 Nov 2011 02:48:26 GMT

Hello,

Try to desactivate the MTU protection on the kinetis, that solved my problem. Now the DMA can access to the memory.

Regards,

Jocelyn

Re: SDHC working with DMA

T_M_F — Thu, 05 Jan 2012 12:23:08 GMT

Can you send you code for me to test on my SDIO WIFI card?

Re: SDHC working with DMA

Muffinman — Tue, 24 Jan 2012 21:13:45 GMT

Can you send me your code? If you can tell me the speed of your SDIO, that will be great.

email me jack@engtech.ca

Re: SDHC working with DMA

Muffinman — Tue, 24 Jan 2012 21:14:18 GMT

Can you send me your code? If you can tell me the speed of your SDIO, that will be great.

Re: SDHC working with DMA

Gargy — Wed, 25 Jan 2012 00:27:33 GMT

Hi,

you are absolutely right, with one mistake.

The name of protection is not MTU, but MPU.

// Switch off MPU unit
MPU_CESR &= ~MPU_CESR_VLD_MASK;

Gargy

Re: SDHC working with DMA

Muffinman — Wed, 25 Jan 2012 20:40:43 GMT

Thanks Gargy,

Did you test the speed with the DMA foe esdhc 4 bit?

Re: SDHC working with DMA

Gargy — Wed, 25 Jan 2012 20:53:41 GMT

Hi,

not yet. This is my hobby project and I don't have enough time for it :smileysad:.

Gargy

Re: SDHC working with DMA

T_M_F — Wed, 25 Jan 2012 23:33:24 GMT

Gargy,

What code are you guys talking about, where can I find it?

Thanks!

Re: SDHC working with DMA

Gargy — Thu, 26 Jan 2012 00:43:44 GMT

Hi I wrote, one pcs of driver myself, but still there is any bug. When I stepping the code, it runs but if I run the code the MCU broke down. :smileyhappy:

Gargy

Re: SDHC working with DMA

Muffinman — Fri, 27 Jan 2012 03:58:30 GMT

The naked speed for the 4 bit SDIO for 100M Hz K60 could be around 40-50M bps. I didn't know if your driver is ready for so fast buffer transceiving? Could you send me the driver for my reference. My email is in theis topic.

Re: SDHC working with DMA

Gargy — Fri, 27 Jan 2012 13:47:15 GMT

Hi,

maybe I just have the developing version (not finished), but why not. More eyes, more see.

I will send it to you when I will be on my home PC.

Gargy

Re: SDHC working with DMA

T_M_F — Fri, 27 Jan 2012 16:08:17 GMT

you can attach it here? i thought.....

what about SDHC with normal SDHC card and not SDIO?

thanks.

Re: SDHC working with DMA

Muffinman — Wed, 01 Feb 2012 04:49:45 GMT

I didn't receive the code, would you like send again?

Re: SDHC working with DMA

Gargy — Wed, 01 Feb 2012 16:22:05 GMT

Hi,

you can't received anything, because I didn't sent you email. Give me few days (up to weekend). I have at the moemnt something function but I want to clear up little bit source code.

Please be more patient.

I looks that it will be works.

Gargy

Re: SDHC working with DMA

Gargy — Fri, 03 Feb 2012 04:33:44 GMT

Hi,

here is my testing project for TWR-K60. It runs on mask 0M33Z. I tested it in IAR 6.21.

So I hope that will help zou, and I also except that zou look inside and all possible bugs or improvements zou are placed on this forum(I'll be more than happy) .

So there is also tested file system FATFS (http://elm-chan.org/fsw/ff/00index_e.html).

The driver is designed just only for SD/SDHC cards.

Enjoy and let me know.

Gargy

Re: SDHC working with DMA

Muffinman — Mon, 13 Feb 2012 22:17:44 GMT

Great, Thanks