eMMC vs HyperFlash

Rayman

Must have been hiding under a rock, but just discovered this eMMC stuff.

If I have it right, it's similar to SPI mode uSD, but with 8-bit bus and high speed.
Maybe I ignored it before due to BGA and lots of balls.
But, when I see it now, only a few of the balls are actually used.
All in all, not much different from HyperFlash.

But, memory size is much bigger with eMMC.
So, why use HyperFlash?
Maybe writing is faster? Just lower cost and size?

Wuerfel_21

SD cards and eMMC chips have a controller handles erasing, wear levelling, read-disturb avoidance, error correction and a bunch of other stuff for you.

Rayman

Looks like Amazon picked HyperFlash for Alexa:
https://www.globenewswire.com/news-release/2019/03/19/1757410/0/en/ISSI-HyperFlash-memory-has-successfully-been-designed-into-the-NXP-i-MX-RT106A-MCU-based-solution-for-AVS-Alexa-Voice-Service.html

They mention putting HyperRam on the same bus as HyperFlash…
Guess HyperBus can be faster than eMMC and physical size is smaller.

Rayman

I can't find any info on the eMMC commands via web search...
Think I'm supposed to buy the JEDEC standard for $327: https://www.jedec.org/standards-documents/docs/jesd84-b51

Let's say I do that... Can I post code based on that standard? I thought this was open...

Ok, think I found Linux code for eMMC:
https://github.com/torvalds/linux/tree/master/drivers/mmc/core

Found some better looking code (and MIT license) here:
https://github.com/starlino/sdEmmc/blob/master/sdEmmc_cmd.c

Usage looks almost exactly like uSD, except can set 8-bit bus width...

Mark_T

eMMC does not support SPI from what I can glean.
eMMC drivers exist for linux, its used in the beaglebone for instance. Its basically an MMC card
in BGA package AFAICT.

jmg

Rayman wrote: »

..
If I have it right, it's similar to SPI mode uSD, but with 8-bit bus and high speed.

There is also OctaRAM and OctaFLASH , but getting OctaRAM does not look easy....
http://www.jeju-semi.com/Products/OctaRAM
https://www.autonomousvehicletech.com/articles/204-jscs-octaram-and-mxics-octaflash-combined
http://www.macronix.com/en-us/products/NOR-Flash/Pages/OctaFlash.aspx#3V

Digikey lists Octaflash
MX25LM51245G $7.32/1k for 512Mb
MX66LM1G45GXDI00 $14.69 for 1Gb

In DTR mode, the Octa- DQS signal, looks the same as the HyperRAM RWDS signal ?

Mark_T

From: https://en.wikipedia.org/wiki/MultiMediaCard#Open_standard

As of 23 September 2008, the MMCA group has turned over all specifications to the JEDEC organization including embedded MMC (e-MMC) and miCARD assets. JEDEC is an organization devoted to standards for the solid-state industry.

As of February 2015, the latest specifications version 5.1 can be requested from JEDEC, and after registering with JEDEC, can be downloaded free-of-charge. Older versions of the standard, as well as some optional enhancements to the standard such as MiCard and SecureMMC, must be purchased separately.

Rayman

Mouser has 8 GB eMMC for $8.70
P/N: SDINBDG4-8G

jmg

Rayman wrote: »

Mouser has 8 GB eMMC for $8.70 P/N: SDINBDG4-8G

Certainly cheaper than OctaFlash, so if you need large storage and are less worried about random access & XIP it could be useful

AntoineDoinel

There are tiny eMMC modules available at www.hardkernel.com that could be slightly easier to solder, haven't checked but I think the matching micro connector should be identifiable by looking at the schematics available in the product page.
Also, there is an adapter allowing to plug the module into a micro SD card slot (I guess not in 8bit mode though).

Might be useful at least for the first tests, hope it helps.

Rayman

I'm thinking that the pinout must be part of the JEDEC standard.
Most of the datasheets don't have it.
This one did though.
Looks really easy to route as most balls are not internally connected.

Cluso99

Makes you wonder what engineer decided these pinouts

rogloh

Just came across this stuff on eMMC on an engineer's linked in page of all places...

https://www.linkedin.com/pulse/emmc-implementation-ignacio-diz-castro

I was wondering about that strange "DS" pin in the pinout image Rayman posted and it thankfully seems it can be ignored unless you want to operate in the new high speed HS400 mode according to him. If the protocol is simply MMC which is reasonably well documented online, it might be possible to just experiment with one without buying the official specs and see how it behaves, assuming you build a board (or get some other pre-loaded version on some other PCB board). I know some Raspi clones like Rock Pi, Rock 64 etc use/provide cheap breakouts for eMMC using a simpler connector so it might be good to start with that.

Rayman

plus, we have to figure this out to crack iPhone data...
Just saw that this is the memory chips inside iPhones...

Cluso99

I bet they are heavily encrypted.

potatohead

They are. Encryption handled in secure enclave on iPhone.

Rayman

Looks like HyperBus is also referred to now as "JEDEC xSPI"...
https://www.cypress.com/news/cypress-hyperbus-memory-interface-instant-applications-incorporated-jedec-xspi-electrical

whicker

Sigh... marketing.

cross point memory had an X, let's confuddle the suits and investors, and put an 'x' in our new name as well.

Wuerfel_21

When are we getting the "hyper X-treme turbo advance blockchain AI XXXFLASH 3000 & Knuckles"?

Rayman

It may not be entirely marketing. If you look at the bottom, you can see a graphic that shows how xSPI devices can share the same bus.

But, searching for xSPI is not easy, hard to find what kind of xSPI devices might exist...

Rayman

I see HyperFlash has a much higher sustained read rate.
Good if you're trying to execute from memory...

Rayman

I home hyperram and emmc can share same bus...

Rayman

I noticed the thickness of emmc depends on capacity...
They must be stacking inside...

Rayman

Decided to go back to work designing an eMMC board to try out.

But then, it occurred to me that I should take another look at what I can just buy...
Found some nice ones here: https://ameridroid.com/products/emmc-5-1-module-blank
But, they have a connector that is hard to come by...

Then, found this one (see attached). Much easier connector. And, it's on Amazon...
Ordered today... Should get one Saturday!

JRoark

@Rayman Is this the same critter you ordered?

https://www.amazon.com/eMMC-Module-8GB-NanoPi-M4/dp/B07JVMSHBX/ref=mp_s_a_1_1?dchild=1&keywords=B07JVMSHBX&qid=1589501589&sr=8-1

Rayman

Looks like it but mine is 16 gb and more expensive...

youyeetoo eMMC Module - 16GB

I couldn’t find a 8 gb one when I looked...

Rayman

The ones from overseas are a lot cheaper but who knows when they’d get here...

Yanomani

There are also adapters to enable them to be accessed as MicroSD cards. Not cheap as peanuts, but, perhaps, could worth a try.

Rayman

There’s a usb3 adapter for the other style too...

Just wished they’d picked an easier to find connector...

You can get the .4 mm pitch connectors on eBay from overseas but who knows when they’d get here...

The .1 inch 1.27 mm pitch connector version is much nicer although I do wish for a usb3 adapter for that one.

Yanomani

Doesn't AmeriDroid's eMMC adapter fill your expectations from where to pull a connector?

Sure, not as fresh as a brand new unit, after pulling, but in the US, at least...

The price tag seems right, at least to me, for a unit you can put your hands on, without having to be affraid, waiting for an unknown arrival date.

https://ameridroid.com/products/emmc-adapter

Yanomani

Both GB042-series, 1mm height, .4mm pitch connectors (GB042 - 34S - H10 - E3000 and GB042 - 34P - H10 - E3000) are available (stocked) at:

Dana Microsystems, Inc. - Sales
Av. Lazaro Cardenas #3454
Col. Jardines Chapalita
Guadalajara, Jal., C.P. 44520, Mexico
sales@danamicro.com

https://danamicro.com/

I didn't contacted them, thus I'm unsure for any minimum quantities/order totals that could apply, but they are closer than any other China parts provider.

I'm also unsure of brand, perhaps LS Electronic Components (separated from LG in 2005) or any other suitable alternative.

Hope it helps.