SD Specifications
Part 1
Physical Layer
Simplified Specification
Version 4.10
January 22, 2013
SD Group
Panasonic Corporation
SanDisk Corporation
Toshiba Corporation
Technical Committee
SD Card Association
©Copyright 2001-2013 SD Group (Panasonic, SanDisk, Toshiba) and SD Card Association
Physical Layer Simplified Specification Version 4.10
i
Revision History
Date
Version
Changes compared to previous issue
April 3, 2006 1.10
Physical Layer Simplified Specification Version 1.10 initial release.
(Supplementary Notes Ver1.00 is applied.)
September 25, 2006
2.00
Physical Layer Simplified Specification Version 2.00
May 18, 2010
3.01
Physical Layer Simplified Specification Version 3.01
January 22, 2013
4.10
Physical Layer Simplified Specification Version 4.10
To the extent this proposed specification, which is being submitted for review under the IP
Policy, implements, incorporates by reference or refers to any portion of versions 1.0 or 1.01
of the SD Specifications (including Parts 1 through 4), adoption of the proposed specification
shall require Members utilizing the adopted specifica
tion to obtain the appropriate licenses
from the SD-3C, LLC, as required for the utilization of those portion(s) of versions 1.0 or 1.01
of the SD Specifications.
For example, implementation of the SD Specifications in a host device under versions 1.0 or
1.01 and under the adopted specification requires the execution of a SD Host Ancillary
License Agreement with the SD-3C, LLC; and implementation of the SD Specifications under
versions 1.0 or 1.01 and under the proposed specification in a SD Card containi
ng any
memory storage capability (other than for storage of executable code for a controller or
microprocessor within the SD Card) requires the execution of a SD Memory Card License
Agreement with the SD-3C, LLC.
©Copyright 2001-2013 SD Group (Panasonic, SanDisk, Toshiba) and SD Card Association
Physical Layer Simplified Specification Version 4.10
ii
Release of SD Simplified Specification
The following conditions apply to the release of the SD simplified specification ("Simplified
Specification") by the SD Card Association. The Simplified Specification is a subset of the complete SD
Specification which is owned by the SD Card Association.
Conditions for publication
Publisher and Copyright Holder:
SD Card Association
2400 Camino Ramon, Suite 375
San Ramon, CA 94583 USA
Telephone: +1 (925) 275-6615,
Fax: +1 (925) 886-4870
E-mail: office@sdcard.org
Notes:
This Simplified Specification is provided on a non-confidential basis subject to the disclaimers below.
Any implementation of the Simplified Specification may require a license from the SD Card Association
or other third parties.
Disclaimers:
The information contained in the Simplified Specification is presented only as a standard specification
for SD Cards and SD Host/Ancillary products and is provided "AS-IS" without any representations or
warranties of any kind. No responsibility is assumed by the SD Card Association for any damages, any
infringements of patents or other right of the SD Card Association or any third parties, which may result
from its use. No license is granted by implication, estoppel or otherwise under any patent or other rights
of the SD Card Association or any third party. Nothing herein shall be construed as an obligation by the
SD Card Association to disclose or distribute any technical information, know-how or other confidential
information to any third party.
©Copyright 2001-2013 SD Group (Panasonic, SanDisk, Toshiba) and SD Card Association
Physical Layer Simplified Specification Version 4.10
iii
Conventions Used in This Document
Naming Conventions
● Some terms are capitalized to distinguish their definition from their common English meaning. Words
not capitalized have their common English meaning.
Numbers and Number Bases
● Hexadecimal numbers are written with a lower case "h" suffix, e.g., FFFFh and 80h.
● Binary numbers are written with a lower case "b" suffix (e.g., 10b).
● Binary numbers larger than four digits are written with a space dividing each group of four digits, as
in 1000 0101 0010b.
● All other numbers are decimal.
Key Words
• May: Indicates flexibility of choice with no implied recommendation or requirement.
• Shall: Indicates a mandatory requirement. Designers shall implement such mandatory
requirements to ensure interchangeability and to claim conformance with the specification.
• Should: Indicates a strong recommendation but not a mandatory requirement. Designers should
give strong consideration to such recommendations, but there is still a choice in
implementation.
Application Notes
Some sections of this document provide guidance to the host implementers as follows:
Application Note:
This is an example of an application note.
©Copyright 2001-2013 SD Group (Panasonic, SanDisk, Toshiba) and SD Card Association
Physical Layer Simplified Specification Version 4.10
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Table of Contents
1. General Description ............................................................................................................ 1
2. System Features ................................................................................................................. 3
3. SD Memory Card System Concept .................................................................................... 5
3.1 Read-Write Property ................................................................................................................... 5
3.2 Supply Voltage ............................................................................................................................ 5
3.3 Card Capacity ............................................................................................................................. 5
3.3.1 User Area and Protected Area .............................................................................................. 5
3.3.2 Card Capacity Classification ................................................................................................. 5
3.4 Speed Class ............................................................................................................................... 5
3.5 Bus Topology .............................................................................................................................. 6
3.6 Bus Protocol ............................................................................................................................... 7
3.6.1 SD Bus Protocol ................................................................................................................... 7
3.6.2 SPI Bus Protocol ................................................................................................................ 10
3.6.3 UHS-II Bus Protocol ........................................................................................................... 10
3.7 SD Memory Card–Pins and Registers ....................................................................................... 11
3.7.1 SD Bus Pin Assignment ....................................................................................................... 11
3.7.2 UHS-II Pin Assignment ....................................................................................................... 13
3.8 ROM Card ................................................................................................................................ 14
3.8.1 Register Setting Requirements ........................................................................................... 14
3.8.2 Unsupported Commands .................................................................................................... 14
3.8.3 Optional Commands ........................................................................................................... 14
3.8.4 WP Switch .......................................................................................................................... 14
3.9 Ultra High Speed Phase I (UHS-I) Card .................................................................................... 15
3.9.1 UHS-I Card Operation Modes ............................................................................................. 15
3.9.2 UHS-I Card Types .............................................................................................................. 15
3.9.3 UHS-I Host and Card Combination ..................................................................................... 16
3.9.4 UHS-I Bus Speed Modes Selection Sequence ................................................................... 17
3.9.5 UHS-I System Block Diagram ............................................................................................. 18
3.9.6 Summary of Bus Speed Mode for UHS-I Card ................................................................... 19
3.10 Ultra High Speed Phase II (UHS-II) Card ................................................................................ 20
3.10.1 UHS-II Card Operation Modes .......................................................................................... 20
3.10.2 UHS-II Card Type ............................................................................................................. 20
3.10.3 UHS-II Host and Card Combination .................................................................................. 20
3.10.4 UHS-II Interface Selection Sequence ............................................................................... 21
3.10.5 Summary of Bus Speed Mode for UHS-II Card ................................................................. 23
4. SD Memory Card Functional Description ....................................................................... 24
4.1 General ..................................................................................................................................... 24
4.2 Card Identification Mode ........................................................................................................... 25
4.2.1 Card Reset ......................................................................................................................... 25
4.2.2 Operating Condition Validation ........................................................................................... 25
4.2.3 Card Initialization and Identification Process ...................................................................... 27
4.2.3.1 Initialization Command (ACMD41) .......................................................................................... 29
4.2.4 Bus Signal Voltage Switch Sequence ................................................................................. 30
