C6748 boot speed - eMMC vs. parallel NOR

Bernhard Boehmer

Other Parts Discussed in Thread: OMAPL138, OMAP-L138

Hello TI,

We are investigating booting our C6748-based design from eMMC instead of the 16-bit parallel NOR interface which we have traditionally been using. The latest eMMC parts available support the eMMC v.5 standard and are sized 2GB and up. We run our own SysBios-based OS. We use the SecureBoot versions of the C6748 and thus do not wish to use a Secondary Bootloader in order to avoid booting in the clear.

1) It is not quite apparent whether we could use the eMMC boot option in 8-bit mode. Is this possible?

2) If so, equivalent or better boot speeds might arguably be expected compared to 16-bit NOR boot (both with optimised timing). Our image is approx. 16MB. Does anyone have practical experience here?

3) Any other boot-related issues we should be aware of in the light of the currently available eMMC offering (eg. 2GB limit)?

Regards,

Bernhard

over 11 years ago

0 Sivaraj Kuppuraj over 11 years ago

TI__Mastermind 35645 points

Hi,

It is been assigned to right experts and your query will be addressed soon.

Thanks & regards,

Sivaraj K

0 Titusrathinaraj Stalin over 11 years ago

TI__Guru** 116100 points

Hi Bernhard,

Please refer OMAPL138 bootloader doc chapter 6.5

http://www.ti.com/general/docs/lit/getliterature.tsp?baseLiteratureNumber=sprab41&fileType=pdf

http://processors.wiki.ti.com/index.php/Basic_Secure_Boot_for_OMAP-L138_C6748

http://processors.wiki.ti.com/index.php/OMAP-L138_Bootloader

0 Bernhard Boehmer over 11 years ago in reply to Titusrathinaraj Stalin

Expert 1120 points

Hello Titus,

Thank you. Please confirm that booting via eMMC in 8-bit mode is possible - I do not see this stated overtly in the documents you reference.

Bernhard

0 Titusrathinaraj Stalin over 11 years ago in reply to Bernhard Boehmer

TI__Guru** 116100 points

Hi Bernhard,

As per the below thread, One customer not able to work with 4 0r 8 bit but 1 bit does work.

http://e2e.ti.com/support/dsp/omap_applications_processors/f/42/t/289684.aspx

http://e2e.ti.com/support/dsp/omap_applications_processors/f/42/t/290019.aspx

0 Bernhard Boehmer over 11 years ago in reply to Titusrathinaraj Stalin

Expert 1120 points

Hello Titus, what was the consensus?

0 Titusrathinaraj Stalin over 11 years ago in reply to Bernhard Boehmer

TI__Guru** 116100 points

Hi Bernhard,

Sorry for the delayed response.

I asked one of our experts and He will reply soon.

Thanks for your patience.

0 Mukul Bhatnagar over 11 years ago in reply to Titusrathinaraj Stalin

TI__Guru* 84035 points

Hi Bernhard

Sorry for the delay

I reconfirm what Titus mentioned , the device RBL for SDMMC boot mode RBL uses 4 bit bus width for SD card and 1 bit for eMMC. Post boot you can reconfigure for 8bit bit eMMC etc (secondary boot loader or application usage).

We had done testing with managed nand parts from Micron. You can evaluate parts like MTFC4GACAAAM etc.

There are some coarse bench marks for boot (i don't believe we have it specifically for eMMC boot) that you will find here

http://processors.wiki.ti.com/index.php/OMAP-L138_Boot_Benchmarks

In general the ROM adds a bunch of delay loops/dead cycles to ensure functionality over speed, and typically eMMC cards have their own init time requirements too.

It would be best to test the performance out yourself for the eMMC cards/vendors you have under evaluation.

Hope this helps.

Regards

Mukul

0 Bernhard Boehmer over 11 years ago in reply to Mukul Bhatnagar

Expert 1120 points

Hello Mukul,

Thank you for the reply and confirmation. Is there any hope for a RBL update which might include 8-bit eMMC boot with configurable parameters?

Bernhard

0 Mukul Bhatnagar over 11 years ago in reply to Bernhard Boehmer

TI__Guru* 84035 points

Hi Bernhard

Unfortunately there are no plans to spin the silicon to update the on chip ROM to support any newer features.

We have recently release Revision 2.3, but the only thing that was updated/fixed on this was an USB PHY PLL temperature sensitivity errata.

Regards

Mukul

0 Bernhard Boehmer over 11 years ago in reply to Mukul Bhatnagar

Expert 1120 points

Hello Mukul,

By the way, here are estimated C6748 DSP boot times (1KB and 124kB benchmarks as well as formula for estimating boot times for other image sizes obtained from TI wiki: http://processors.wiki.ti.com/index.php/OMAP-L138_Boot_Benchmarks):

Device	Boot Mode	Boot Time (ms)		Estimated Boot Time (ms) (excludes mDDR copy time)
Device	Boot Mode	1KB	124KB	1MB (thus also approx. ms/MB)
C6748	NAND8	60	80	226.5
	NAND16	36	52	169.2
	NOR (parallel)	3	15	102.9
	SPI Flash	4	96	769.9
	SD	34	195	1374.4
	SDHC	42	180	1190.9
	MMC (1-bit)	68	84	201.2
	MMC (8-bit), estimated if supported by RBL, which it unfortunately currently is not			25.2

Is this calculation correct?

0 FrankXu over 8 years ago in reply to Mukul Bhatnagar

Genius 3500 points

Hi Mukul,

I am dealing with eMMC and see your discussion.

You mentioned "You can evaluate parts like MTFC4GACAAAM etc."

But I looked at MTFC4GACAAAM's datasheet, it is "JEDEC/MMC standard version 4.51-compliant".

While the C6748 "The MultiMedia Card/Secure Data (MMC/SD) boot mode is compliant with version 2.0 of the SD
specification and version 4.2 of the enhanced MultiMedia Card (eMMC) specification."

Can C6748 boot with MTFC4GACAAAM?

And, is there any driver program for the eMMC? As I only get the MMCSD project in Startware, which is a test program for the SD card. Does it also work for eMMC?

And, can the region of the eMMC beyond the boot image be treated as a file system?

Thank you.

Frank

0 Mukul Bhatnagar over 8 years ago in reply to FrankXu

TI__Guru* 84035 points

Hi Frank
Similar to my response on your other post
e2e.ti.com/.../2094659

Yes we expect that MT4C4GACAAAM to work with the rom boot loader , I believe one customer has taken this to production in their system with OMAPL138.
The OMAPL138 has the ARM ROM Boot loader and C6748 has the DSP ROM Boot loader, but this aspect of the code base for emmc boot is the same so it should also work with c6748.

However in general as you noted, our offerings on the DSP side for MMC/SD drivers etc is not strong , compared to a lot more support you will find on the ARM side for OMAPL138.

Regards
Mukul

0 FrankXu over 8 years ago in reply to Mukul Bhatnagar

Genius 3500 points

Hi Mukul,

Got it.
Thank you very much.

Frank

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C6748 boot speed - eMMC vs. parallel NOR