eMMC as  Flash memory - Page 1
Forum section: electronics / projects

author: rakeshm55
author_rank: Regular Contributor
timestamp: June 22, 2018, 07:04:44 am
content: In of one of my project I will be using AM5718 Sitara series as the main application processor.Reference Design would be fromhttp://www.ti.com/tool/tmdxidk5718.It uses SD card or eMMC as Flash memory. Since product is vibration hardened I am left with eMMC as Main Flash memory solution.Since the longevity of the product is for 10years or more will it be a wise decision to go with eMMC as Flash memory solution.What are the other options?Will the device wearout fast? Should I make a plug-able version ??Thnx in Advance

author: rakeshm55
author_rank: Regular Contributor
timestamp: June 22, 2018, 09:19:34 am
content: eMMC comes in 0.5mm pitch153 BGA...Any SD card solution for automotive application/suitable connector....Any alternative

author: amyk
author_rank: Super Contributor
timestamp: June 22, 2018, 11:16:38 am
content: A microSD card + socket might be better.

author: daveshah
author_rank: Unknown
timestamp: June 22, 2018, 11:30:19 am
content: I would have thought if you are able to use the Sitara, then the eMMC package wouldn't be a major problem either - many of the balls are unused so breakout isn't excessively difficult.

author: rakeshm55
author_rank: Regular Contributor
timestamp: June 22, 2018, 02:47:26 pm
content: Quote from: amyk on June 22, 2018, 11:16:38 amhow to handle vibration in this case??...OS will reside in SD flash in this case...What precaution to achieve vibration spec. Is there any guideline ??

author: rakeshm55
author_rank: Regular Contributor
timestamp: June 22, 2018, 02:56:37 pm
content: Quote from: daveshah on June 22, 2018, 11:30:19 am...Sitara AM5718 has a pitch of 0.8mm and we have made boards with this pitch without using microvias...since no of useful pins are abt 14 for eMMC it may be possible I don't know ...

author: sd
author_rank: Unknown
timestamp: June 22, 2018, 07:08:06 pm
content: eMMC also comes in 1mm pitch, check the 100-ball devices here:https://www.micron.com/products/managed-nand/emmc/automotive-emmc#/

author: loganrf
author_rank: Newbie
timestamp: June 24, 2018, 06:55:34 pm
content: I was just working on an embedded project myself (albeit Zynq based) and we decided to steer clear of eMMC. The main issue with eMMC is that the greater the bit-density, the lower the lifespan. They're doing better with some of the new technologies, but I'd still be worried about memory failures if you plan on the product lasting 10 years. If you do go with eMMC, try to see if you can get away with SLC. It doesn't have much memory capacity, but it will generally last longer. As some of the others have said, socket and SD is really the best option though.

author: ruffy91
author_rank: Regular Contributor
timestamp: June 24, 2018, 07:24:04 pm
content: A problem is that eMMC will loose its content when unpowered. The higher the temperature the faster.10 years should be doable. For example Sandisk iNAND 4.51/HS200 gives 10 years at 55°C when you stay under 10% of rated write also 100k read cycles of the same cell when under 10%You could rewrite often read blocks as refresh every month/year or so to stay safe.

author: rakeshm55
author_rank: Regular Contributor
timestamp: June 25, 2018, 12:47:44 pm
content: Quote from: loganrf on June 24, 2018, 06:55:34 pmOther than SLC how about pSLC??I am not particular about density. Anything greater than 2GB will do.From Micron ""A part or all of the MLC user space can be configured as pseudo-SLC. The partition offers better reliability, endurance, and performance compared to MLC NAND.""Choice of eMMC over SD card is just for vibration and wide temperature range. How to meet vibration requirements using SD card??