sd standards and sd technology - home - sd association · pdf filesd standards and sd...
TRANSCRIPT
© 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
© 2014 SD Association. All rights reserved. 2
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
© 2014 SD Association. All rights reserved. 4
SD Standard Direction for High Speed Interface
UHS‐II Gen2
© 2014 SD Association. All rights reserved. 5
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
© 2014 SD Association. All rights reserved. 7
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
SDR50 100MHz 1.8V 50MB/sec
SDR104 208MHz 1.8V 104MB/sec
DDR50 50MHz 1.8V 50MB/sec
UHS‐II FD156 52MHz x30 LVDS 156MB/sec 4.004.20HD312 52MHz x30 LVDS 312MB/sec
© 2014 SD Association. All rights reserved. 8
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.
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
© 2014 SD Association. All rights reserved.
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
© 2014 SD Association. All rights reserved.
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
© 2014 SD Association. All rights reserved.
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
© 2014 SD Association. All rights reserved.
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)
© 2014 SD Association. All rights reserved. 16
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
© 2014 SD Association. All rights reserved.
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)
© 2014 SD Association. All rights reserved.
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
storageISO 7816-3 APDU over ASSD or file I/OmicroSD storage
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
storageISO 7816-3 APDU over ASSD or file I/OmicroSD storage
Java card
SE with GP &
Java card
smart microSD without NFCsmart microSD features an SE that is accessiblethrough ASSD for host applications
© 2014 SD Association. All rights reserved.
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
© 2014 SD Association. All rights reserved.
smart microSD Applications
20
NFC Security token
SecureElement
Mobile Payment
Online payment
Authentication
Transportation
Secure storage
And many more
© 2014 SD Association. All rights reserved.
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
© 2014 SD Association. All rights reserved.
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
© 2014 SD Association. All rights reserved.
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.