©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
