文件名称：SD卡 物理层协议
文件大小：1.05MB
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更新时间：2013-08-23 09:36:30
SD 卡 协议
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 3.4 Speed Class ..................................................................................................................................6 3.5 Bus Topology .................................................................................................................................7 3.6 Bus Protocol ..................................................................................................................................7 3.6.1 SD Bus....................................................................................................................................7 3.6.2 SPI Bus .................................................................................................................................10 3.7 SD Memory Card–Pins and Registers......................................................................................... 11 4. SD Memory Card Functional Description .......................................................................12 4.1 General ........................................................................................................................................12 4.2 Card Identification Mode..............................................................................................................13 4.2.1 Card Reset ............................................................................................................................13 4.2.2 Operating Condition Validation..............................................................................................13 4.2.3 Card Initialization and Identification Process ........................................................................15 4.3 Data Transfer Mode.....................................................................................................................17 4.3.1 Wide Bus Selection/Deselection ...........................................................................................19 4.3.2 2 GByte Card ........................................................................................................................19 4.3.3 Data Read.............................................................................................................................19 4.3.4 Data Write .............................................................................................................................20 4.3.5 Erase.....................................................................................................................................22 4.3.6 Write Protect Management ...................................................................................................22 4.3.7 Card Lock/Unlock Operation.................................................................................................23 4.3.7.1 General ................................................................................................................................. 23 4.3.7.2 Parameter and the Result of CMD42.................................................................................... 25 4.3.7.3 Forcing Erase ....................................................................................................................... 27 4.3.7.3.1 Force Erase Function to the Locked Card...................................................................... 27 4.3.7.4 Relation Between ACMD6 and Lock/Unlock State................................................................ 28 4.3.7.5 Commands Accepted for Locked Card ................................................................................. 28 4.3.7.6 Two Types of Lock/Unlock Card............................................................................................ 29 4.3.8 Content Protection ................................................................................................................29 4.3.9 Application-Specific Commands............................................................................................29 4.3.9.1 Application-Specific Command – APP_CMD (CMD55)......................................................... 29 4.3.9.2 General Command - GEN_CMD (CMD56) ........................................................................... 30 4.3.10 Switch Function Command .................................................................................................31 4.3.10.1 General ............................................................................................................................... 31 4.3.10.2 Mode 0 Operation - Check Function ................................................................................... 32 4.3.10.3 Mode 1 Operation - Set Function........................................................................................33 4.3.10.4 Switch Function Status........................................................................................................ 35 4.3.10.4.1 Busy Status Indication for Functions ............................................................................ 36 4.3.10.4.2 Data Structure Version ................................................................................................. 37 4.3.10.4.3 Function Table of Switch Command............................................................................. 37 4.3.10.5 Relationship between CMD6 data & other commands ....................................................... 38 4.3.10.6 Switch Function Flow Example...........................................................................................38 4.3.10.7 Example of Checking.......................................................................................................... 38 4.3.11 High-Speed Mode (25 MB/sec interface speed)..................................................................39 4.3.12 Command System...............................................................................................................39 4.3.13 Send Interface Condition Command (CMD8) .....................................................................40 4.3.14 Command Functional Difference in High Capacity SD Memory Card.................................41 4.4 Clock Control ...............................................................................................................................42 4.5 Cyclic Redundancy Code (CRC) .................................................................................................43 4.6 Error Conditions...........................................................................................................................45 4.6.1 CRC and Illegal Command ...................................................................................................45 4.6.2 Read, Write and Erase Timeout Conditions ..........................................................................45 4.6.2.1 Read ..................................................................................................................................... 45 4.6.2.2 Write ..................................................................................................................................... 45 4.6.2.3 Erase .................................................................................................................................... 45 4.7 Commands ..................................................................................................................................46 4.7.1 Command Types ...................................................................................................................46 4.7.2 Command Format .................................................................................................................46 4.7.3 Command Classes................................................................................................................46 4.7.4 Detailed Command Description ............................................................................................49 4.8 Card State Transition Table .........................................................................................................56 4.8 Card State Transition Table .........................................................................................................56 4.9 Responses...................................................................................................................................58 4.9.1 R1 (normal response command):..........................................................................................58 4.9.2 R1b........................................................................................................................................58 4.9.3 R2 (CID, CSD register) .........................................................................................................58 4.9.4 R3 (OCR register) .................................................................................................................59 4.9.5 R6 (Published RCA response) ..............................................................................................59 4.9.6 R7 (Card interface condition) ................................................................................................59 4.10 Two Status Information of SD Memory Card .............................................................................61 4.10.1 Card Status .........................................................................................................................61 4.10.2 SD Status ............................................................................................................................65 4.11 Memory Array Partitioning .........................................................................................................68 4.12 Timings ......................................................................................................................................68 4.13 Speed Class Specification .........................................................................................................69 4.13.1 Allocation Unit (AU) .............................................................................................................69 4.13.2 Recording Unit (RU)............................................................................................................69 4.13.3 Write Performance ..............................................................................................................69 4.13.4 Read Performance..............................................................................................................69 4.13.5 Performance Curve Definition.............................................................................................69 4.13.6 Speed Class Definition........................................................................................................69 4.13.7 Consideration for Inserting FAT Update during Recording..................................................70 4.13.8 Measurement Conditions and Requirements of the Speed Class.......................................70 4.14 Erase Timeout Calculation.........................................................................................................71 4.14.1 Erase Unit ...........................................................................................................................71 4.14.2 Case Analysis of Erase Time Characteristics......................................................................71 4.14.3 Method for Erase Large Areas ............................................................................................72 4.14.4 Calculation of Erase Timeout Value Using the Parameter Registers ..................................72 5. Card Registers ..................................................................................................................73 5.1 OCR register................................................................................................................................74 5.2 CID register .................................................................................................................................75 5.3 CSD Register...............................................................................................................................77 5.3.1 CSD_STRUCTURE ..............................................................................................................77 5.3.2 CSD Register (CSD Version 1.0) ..........................................................................................78 5.3.3 CSD Register (CSD Version 2.0) ..........................................................................................86 5.4 RCA register ................................................................................................................................89 5.5 DSR register (Optional) ...............................................................................................................89 5.6 SCR register ................................................................................................................................89 6. SD Memory Card Hardware Interface..............................................................................91 6.1 Hot Insertion and Removal ..........................................................................................................91 6.2 Card Detection (Insertion/Removal) ............................................................................................91 6.3 Power Protection (Insertion/Removal) .........................................................................................91 6.4 Power Scheme ............................................................................................................................91 6.4.1 Power Up ..............................................................................................................................91 6.4.2 Power Down and Power Cycle..............................................................................................92 6.5 Programmable Card Output Driver (Optional) .............................................................................92 6.6 Bus Operating Conditions............................................................................................................92 6.7 Bus Timing (Default) ....................................................................................................................92 6.8 Bus Timing (High-Speed Mode)...................................................................................................92 7. SPI Mode............................................................................................................................93 7.1 Introduction..................................................................................................................................93 7.2 SPI Bus Protocol .........................................................................................................................93 7.2.1 Mode Selection and Initialization...........................................................................................94 7.2.2 Bus Transfer Protection.........................................................................................................96 7.2.3 Data Read.............................................................................................................................96 7.2.4 Data Write .............................................................................................................................97 7.2.5 Erase & Write Protect Management......................................................................................98 7.2.6 Read CID/CSD Registers......................................................................................................99 7.2.7 Reset Sequence....................................................................................................................99 7.2.8 Error Conditions ....................................................................................................................99 7.2.9 Memory Array Partitioning.....................................................................................................99 7.2.10 Card Lock/Unlock................................................................................................................99 7.2.11 Application Specific Commands ..........................................................................................99 7.2.12 Content Protection Command.............................................................................................99 7.2.13 Switch Function Command ...............................................................................................100 7.2.14 High-Speed Mode .............................................................................................................100 7.2.15 Speed Class Specification.................................................................................................100 7.3 SPI Mode Transaction Packets .................................................................................................101 7.3.1 Command Tokens ...............................................................................................................101 7.3.1.1 Command Format ............................................................................................................... 101 7.3.1.2 Command Classes ............................................................................................................. 101 7.3.1.3 Detailed Command Description .......................................................................................... 102 7.3.1.4 Card Operation for CMD8 in SPI mode .............................................................................. 108 7.3.2 Responses ..........................................................................................................................109 7.3.2.1 Format R1........................................................................................................................... 109 7.3.2.2 Format R1b......................................................................................................................... 109 7.3.2.3 Format R2............................................................................................................................110 7.3.2.4 Format R3............................................................................................................................110 7.3.2.5 Formats R4 & R5 .................................................................................................................111 7.3.2.6 Format R7............................................................................................................................111 7.3.3 Control Tokens .................................................................................................................... 111 7.3.3.1 Data Response Token..........................................................................................................111 7.3.3.2 Start Block Tokens and Stop Tran Token..............................................................................111 7.3.3.3 Data Error Token..................................................................................................................112 7.3.4 Clearing Status Bits............................................................................................................. 113 7.4 Card Registers........................................................................................................................... 114 7.5 SPI Bus Timing Diagrams.......................................................................................................... 114 7.6 SPI Electrical Interface .............................................................................................................. 114 7.7 SPI Bus Operating Conditions................................................................................................... 114 7.8 Bus Timing................................................................................................................................. 114 8. SD Memory Card Mechanical Specification .................................................................115 Appendix A..........................................................................................................................116 A.1 Connector.................................................................................................................................. 116 A.2 Related Documentation............................................................................................................. 116 Appendix B..........................................................................................................................117 B.1 Abbreviations and terms............................................................................................................ 117