Learning Time eMMC Basic Knowledge (part 1)
Learning Time > Mobile Phone RF Cellular part 1 <
Mobile phones need Storage to store the main firmware or operating system, in android phones density of storage need to be larger than before, mobile phone manufacture need to use NAND based FLASH memory, the newest technology to the NAND based FLASH memory that use in mobile phones is UFS ( universal flash storage ) we will talk about UFS later, now we will talk about technology before UFS, yes... we will talk about storage named eMMC
embadded MULTI MEDIA CARD or embadded NAND is a NAND BASED FLASH MEMORY CHIP + CONTROLER, the controler contains MCU and internal LDO, that make the communication between NAND and the HOST more fast, use 8 PIN of DATA, 1 PIN of CMD and 1 PIN of CLK.
this eMMC need two supplies, one is VCC ( VDDF ) and the another supplies is VCCQ ( VDD ) as positive supplies chain, and VSS will conected to the system GND just like ussual, we arent need to supply anything to the PIN named VDDI ( this PIN are used to access bank capasitor for the internal LDO only )
there are another PIN named RST, this pin use for executing the hardware reset function and fully controlled by the host.
many packages for eMMC products tha avaliable on the mobile phone market, at lease we found 7 packages that used in many many of mobile phones :
- FBGA 153 ( used as eMMC and eMCP products )
- FBGA 169 ( used as eMMC and eMCP products )
- FBGA 162 ( used as eMCP products )
- FBGA 186 ( used as eMCP products )
- FBGA 221 ( used as eMCP products )
- FBGA 529 ( used as eMCP products )
- FBGA 254 ( used as eMCP products )
eMCP is MULTI CHIP PACKAGE based eMMC, means in one IC have two hardware that not related each other ( so its called MULTI CHIP ) one is eMMC hardware and the other is RAM hardware
if you found eMMC 153 / 169 package, you must see the label name to know what ic is it ( eMMC only or eMCP ) for examples if you found 153 / 169 chip from samsung you can see the label if it "KL" ( this is eMMC only ) and if it "KM" ( this is eMCP ) For SKhynix it is H2 and H9 and for Sandisk it is DU and DP, its ok... i will tell you about it in the another sesion, now we are back to the topic.. So.. eMMC / eMCP in package FBGA 153 and 169 is possible, you just need to know how to read the label name on the package, the good news is both of eMMC dan eMCP is still have a eMCP hardware inside it, and offcourse have a eMMC PIN that wa alread discuss before, the pin map for FBGA 153 and 169 is totally same for the MAIN PIN, the different between them : 169 have 16 GND PIN more in the right and left side
eMMC that use package FBGA 153 / 169, have so many PIN that DO NOT USED ( DNU ) or NOT CONNECTED ( NC ) because only eMMC pin that used in this IC, you know about this eMMC PIN, DAT 0, DAT1, DAT2, DAT3, DAT4, DAT5, DAT6, DAT7, CMD, CLK, VCC, VCCQ, GND, RST, VDDI. and the other is NC / DNU.
eMCP that use package FBGA 153 / 169, have less PIN that DNU or NC, becouse besides eMMC PIN there is RAM PIN, you can see to the picture the RAM PIN, they have another VCC and VCCQ for RAM, they HAVE 32 PIN for DATA ( IO ) and many other, this is why in the eMCP we will found less PIN that NC / DNU. Please becarefull when you faced phone that should be have 16 GB ROM and when you open it you found that phone use 153 / 169 package, make sure this phone need eMMC or need eMCP chip instead.
IF IT NEED eMCP !! :
1. you can not let any of eMMC PIN and RAM PIN broken, please make sure all eMMC PIN and RAM PIN still ok in the phone PCB and please USE eMCP IC's only for replacing
2. you cant USE eMMC models for this phone, i mean you cant USE KLMAG2GE2A-A001, KLMAG2WEMB-B031, KLMAG2GE4A-A001, KLMAG4FE4B-B002, KLMAG4FEAB-B002, KLMAG4FEAB-A002 .... yes i know thoose eMMC is 16 GB ROM but they doesnt have RAM inside it, so in this case you need to use eMCP such as KMVTU000LM-B503, KMVYL000LM-B503, KMV2W000LM-B506, KMV3U000LM-B304, KMV3W000LM-B310 thoose ic have 16 GB of ROM and 1 GB LPDDR1 of RAM. ( for 153 / 169 package if it is eMCP the RAM inside it is always LPDDR1 technology )
If you found some phone only need eMMC in that spot ( some phone use another IC as RAM ) so you have no problem, you can use eMMC ic or eMCP, both of this IC have eMMC inside it, you only need to pay attantion to the ROM density that needed by the phones, and offcourse ic dimension. just for note : sometime you need to noted that EXT_CSD rev 1.6 eMMC can not be use in to phone that instaled android 5.0 and above or depend on thier CPU support it or not.
when we faced some phone that use eMMC package FBGA 153 / 169, we need to make sure that spot only for eMMC or need RAM also, how to do this ?
There are two simple methode :
1. Visual Check
we can read label name on the package of IC, and googling it, search as many as possible information, that make you sure this one is eMMC only or this one also have RAM inside it, that we called eMCP.
Samsung IC :
- If it KL it was eMMC only
- If it KM it was eMMC + RAM ( known as eMCP )
SK Hynix IC :
- If it H2 it was eMMC only
- If it H9 it was eMMC + RAM ( known as eMCP )
if you wanna know for other brand, you can read our books inside pragmafix software
2. Pin Resistance Check
after ic removal, we will found BGA pads on the PCB, you already know which one is eMMC PIN and which one is RAM PIN based on PIN MAP that i posted before
now all you need to do is check some of RAM PIN on the PCB, if you didnt get the resistance value of it, so that pin might be NC / DNU, so this phone PCB only need eMMC, this is why RAM PIN is not used in this PCB ( this is not weird things, some phone use another IC as RAM, standalone RAM, POP RAM above the CPU, etc )
we can do measurement check to the bga pin in the PCB, just do simple resistance check use ohm meter, just put your red probe to the RAM PIN pad you wanna measure and put the black probe to any system ground of PCB.
from the picture bellow you can vissualy found that some of RAM PIN PAD have a surface layer circuit in the PCB, actualy we dont need to measure when we can see RAM PIN have a circuit on the surface like this, we can assume that RAM PIN is USE by PHONE PCB, and select eMCP for replacement.
if you are not sure enaugh, just remember you always always always can do the resistance check on thoose PIN.
IS NOT WEIRD THINGS !!
Some of phone use eMMC only and some of phone use eMCP, its ordinary things
if that phone need to use eMMC only, the manufacture will put FBGA 153 / 169 eMMC, because there is no another package avaliable for eMMC only ( all of 162/186, 221, 529, 254 must be eMCP )
if some phone designed want to use eMMC + RAM LPDDR 1, package 153 / 169 is avaliable
if some phone designed want to use eMMC + RAM LPDDR 2, their PCB designer have a choose to select any eMCP in 162 / 186 package, because this kind of package is avaliable for LPDDR 2 eMCP technology.
if some phone designed want to use eMMC + RAM LPDDR3, their PCB designer can choose eMCP in 221 package, because this package known as eMCP that their RAM use LPDDR 3 technology
if some phone designed want to use eMMC + RAM LPDDR4, their PCB designer need to choose eMCP in 254 package.
as mobile phone engineers, offcourse we will found some phone use 153/169, another one use 162 / 186. another one use 221 or 529, and another one use 254
the eMMC blocks and RAM blocks is totaly sparate, and have their own connection, have thair own supplies, etc... and not related each other.
Post a Comment