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© 2014 SD Association. All rights reserved. 11

SD Standards and SD Technology ‐ Global Workshop Taipei ‐

Hiroyuki SakamotoCo‐Chair, Technical Committee

SD Association

October 1, 2014


Agenda Today

1. Technical Overview2. SD Specification Overview3. SD Speed Classes and Implementation4. Introducing New Features on SD Card5. Issues on Using SD Card in the Market


Technical Overview


SD Standard Direction for High Speed Interface

UHS‐II Gen2


4K DSLR/Video

>150MB/Sec

4K VideoRecording(4K videos)

Light FieldLensesComputational Photography

~1000MB/s

~700MB/s

~100MB/s(Pick)

~2000MB/s

~400MB/s

High speed Download/Upload

Matching Internal Data I/O

High Capacity / High Speed Drivers

Market Evolution Driving UHS‐II

Caching streamed content• Eliminates bandwidth latency• When no internet access available

4K Smart Phone

4K Tablet

4K Recorder

UHS‐II SD UHS‐II microSD


SD Specification Overview


Bus Speed Modes

SDR : Single Data Rate (Use rising clock edge)DDR: Double Data Rate (Use rising and falling clock edge)UHS: Ultra High SpeedLVDS: Low Voltage Differential Signaling

Bus Speed Mode Maximum Frequency

Signal Voltage

Bus Maximum Performance

Spec.Version

Default Speed (DS) 25MHz 3.3V 12.5MB/sec 1.01

High Speed (HS) 50MHz 3.3V 25MB/sec 1.10

UHS‐I SDR12 25MHz 1.8V 12.5MB/sec 3.01

SDR25 50MHz 1.8V 25MB/sec



DDR50 50MHz 1.8V 50MB/sec

UHS‐II FD156 52MHz x30 LVDS 156MB/sec 4.004.20HD312 52MHz x30 LVDS 312MB/sec


Standard Size SD Card Interface

8

SD Memory Card

1 2 3 4 5 6 7 89

10 1112 13 14 1516 17

SD Memory Card

1 2 3 4 5 6 7 89

10 1112 13 14 1516 17

UHS‐II Interface(Note: UHS‐II microSD pin layout is defined as well)

Basic Pin Assignment

SD/UHS‐I Mode InterfaceCLK: Clock Pin (5)CMD: Command/Response Pin (2)DAT0 ‐ DAT3: 4‐bit Data Pins (7,8,9,1)VDD: 3.3V Power Pin (4)VSS1, VSS2: Ground Pins (3,6)

UHS‐II Interface D0+, D0‐: Lane 0 Differential Data Pins (11,12)D1+, D1‐: Lane 1 Differential Data Pins (15,16)RCLK+, RCLK‐: Reference Clock Pins (7,8)VDD2: 1.8V Power Pin (14)VSS3, VSS4, VSS5: Ground Pins (10, 13,17)

SD CardHost CLK

CMD

DAT[3:0]

SD CardHost RCLK

D0

D1

SD Memory Card

1 2 3 4 5 6 7 89

10 1112 13 14 1516 17

SD Memory Card

1 2 3 4 5 6 7 89

10 1112 13 14 1516 17

UHS‐II FD156

SD CardHost RCLK

D0

D1

UHS‐II HD312

© 2014 SD Association. All rights reserved.

SD Speed Classes and Implementation


User Area is divided by AU (Allocation Unit)– AU Size indicates physical boundary of SD memory card– A set of AU Sizes is defined by specification– Write order of AU may be randomAU is divided by SU (Sub Unit) (including AU=SU)

– Card Performance is the min. average sequential write time to each SU• e.g, C4 = 4MB/sec, C10, U1 = 10MB/sec

– SU is written by multiple of write commands sequentiallySU is divided by RU (Recording Unit)

– A write command writes multiple of RU data at a time (at least one RU)

AU Size and RU Size

10

.......

AUn

SU

AU (Allocation Unit)

User Memory Area

SU (Sub Unit)

RURURU

.......

RU

RU (Recording Unit)

SU

.......

SUAU5

AU4

AU3

AU2

AU1


Speed Class defines Minimum Average Performance– Write Performance of each SU (AU) may differ– Average Write Performance to each SU is more than Speed Class valueThere is No Standard to Define Maximum Speed

– Usually Max. Speed is limited by either bus performance or memory performance• In 4‐bit mode, 1 byte is transferred every 2 clocks• Bus Clock frequency determines bus performance

Example of SU (AU) Performance

11

Write Performance (MB/s)

Time0

SU Write Time

Max. Speed

Class Speed

No Standard to define Max. Speed

SU Write Time SU Write Time


8MB SU

8MB SU

8MB SU

Example Card Configuration of Memory Units

12

6MB

6MB

Memory Blocks

24MB AU6MB

6MB

AU Size Sub Units

• One AU may consist of multiple of memory blocks

• Memory block is allowed to configure Sub Unit boundary mismatch

• Host can manage user area regardless of considering Memory Block Size

• Host writes SU sequentially• Host should prepare SU buffer

• AU Size can be divided by both Memory Block Size and Sub Unit Size• This architecture enables SD Memory Card to use Memory Block which is not match to Sub Unit

• AU Size is limited by the minimum number of AUs

AU order can be random

24MB AU

SequentialWrite

SequentialWrite


UHS Speed Class is defined for UHS bus mode– U1: 10MB/sec– U3: 30MB/sec for 4K Video

Speed Classes and UHS Speed Class

13

SDHC(Large AU)

SDSC(AU =<4MB)

SDHC(AU =<4MB)

SDXC(Large AU)

Default Speed Mode

High Speed Mode

Class 2, 4, 6 (r=0)

r: Ratio of Used RU over an AU0<r<1: Fragmented Writer=0 : Sequential Write to Unused AU

UHS-I and UHS-II UHS Speed Class 1 (10MB/sec, r=0)

UHS Speed Class 3 (30MB/sec, r=0)

Standard Capacity

Class 10 (r=0)

High Capacity Extended Capacity

Class 2, 4, 6 (0<=r<1)

Class 10 (r=0)

Bus Speed Mode


Introducing New Features on SD Card


UHS‐II Ultra High Speed Serial I/F Bus

15

Note:UHS-II Gen2 will be 4 times faster than UHS-II Gen1

1. File copy performance

2. Write performance (CristalDiskMark)


SD Card with Wireless Technologies

Part E7 TransferJet Addendum Part E7 Wireless LAN Addendum

Part 1 NFC Interface AddendumPart A1/A3 Advanced Security

Part E2/E3 Bluetooth Type A/B

NewNew


iSDIO TransferJet

17

iSDIO TransferJet Addendum:- Announced at Photokina 2014 in Sep.

What is TransferJet:- High speed proximate interface- 560Mbps, more than 1000 times faster NFC- 10Gbps range in near future- Transfer rich content (e.g. video data)


Various smart microSD Types

18

Card Cont.

End user

storageISO 7816-3 APDU over ASSD or file I/OmicroSD storage

Java card

SE with GP &

Java card

Contactless smart microSDContactless smart microSD is a self-contained solution for SEand contactless smart card emulation for most microSD hostdevices. SDA doesn’t define the contactless interface

Card Cont.

End user


SWPJava card

SE with GP &

Java card

smart microSD with optional SWPsmart microSD features an SE that is accessiblethrough ASSD for host applications and may connectto the host NFC frontend via SWP

optional

Card Cont.

End user


Java card

SE with GP &

Java card

smart microSD without NFCsmart microSD features an SE that is accessiblethrough ASSD for host applications


smart microSD with HCE

19

Android 4.4

NFC Controller(CLF)

NFCApplication

Mobile Phone equippedCLF and microSD Slot

NFC Reader

Android 4.4HCE Service

Smart micro SD

SE Applet

File I/O or ASSD

Card EmulationMode

NFC Host Applications

Android 4.4 (Kit Kat) provides HCE (Host‐based Card Emulation) for NFC applications

smart microSD has chance to get NFC function using this new route of HCE (red break line)

Higher security level on HCE by using SE in microSD SD I/F


smart microSD Applications

20

NFC Security token

SecureElement

Mobile Payment

Online payment

Authentication

Transportation

Secure storage

And many more


Issues on Using SD Card in the Market


Problem– There is an host which formats SD Memory Card with Non SD

Standard FAT File System Format• Especially, Android hosts

– Use of Non SD STD Format may decreases performance of SD Card• Use of small cluster size deteriorates performance markedly• Use of large cluster size is important for SD Memory Card

– Use of Non SD STD Format may decreases reliability of SD Card• Number of erase/write for flash memory may increase with non SD Format

Solution– Comply with Part 2 SD File System Specification– Use SD Formatter for Windows and Mac OS, downloadable from SDA

public website– Use SD format checker from 3rd party to verify SD format

Non SD Standard Format

22


Problem– There are many hosts which are not using Speed Class Write for

realtime recording– There are some hosts which recommend to use some Speed Class

but not using Speed Class Write– Both cannot exploit SD card performance

Recommended Implementation– Additional API of File system

• Pre‐allocation for Speed Class Write– File system can allocate sequential data area

– Access to SD card from file system• File system should manage user memory area by unit of AU• Perform sequential writes to an AU from top to bottom

– Do not overwrite to the AU• Use of CMD20 controls

– It is used to notice whether or not sequential write follows and improves SD card performance

Support of Speed Class

23


Access limitation to microSD from 3rd party applications

Android “L” (next version) will provide solution by extending SAF (Storage Access Framework) API

Android 4.4 (Kit Kat) Issue on microSD

24

Before Kit Kat Kit Kat

Issue:Common folders (e.g. DCIM) can not shared by 3rd party apps.


Thank you!


www.sdcard.org

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