©Copyright 2000-2011 SD Card Association
SDIO Simplified Specification Version 3.00
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Table of Contents
1. General Description............................................................................................................1
1.1 Definitions......................................................................................................................................1
1.1.1 SDIO Card...............................................................................................................................1
1.1.2 Embedded SDIO.....................................................................................................................1
1.2 SDIO Features...............................................................................................................................1
1.2.1 Common SDIO Features.........................................................................................................1
1.2.2 SDIO Card Features ...............................................................................................................1
1.2.3 Embedded SDIO Device Features..........................................................................................2
1.3 Document Structure.......................................................................................................................3
1.4 Standard SDIO Functions..............................................................................................................3
2. SDIO Signaling Definition ..................................................................................................4
2.1 SDIO Card Types ..........................................................................................................................4
2.2 SDIO Card Modes .........................................................................................................................4
2.2.1 SPI (Card mandatory support) ................................................................................................4
2.2.2 1-bit SD Data Transfer Mode (Card Mandatory Support)........................................................4
2.2.3 4-bit SD Data Transfer Mode (Mandatory for High-Speed Cards, Optional for Low-Speed)...4
2.3 SDIO Host Modes..........................................................................................................................4
2.4 Signal Pins.....................................................................................................................................5
2.4.1 Signal Pins for SDIO Card ......................................................................................................5
3. SDIO Card Initialization ......................................................................................................6
3.1 Initialization Sequence...................................................................................................................6
3.1.1 Initialization by Non-I/O Aware Host........................................................................................6
3.1.2 Initialization by I/O Aware Host ...............................................................................................7
3.2 The IO_SEND_OP_COND Command (CMD5)...........................................................................13
3.3 The IO_SEND_OP_COND Response (R4).................................................................................14
3.4 Special Initialization Considerations for Combo Cards................................................................15
3.4.1 Re-initialize Both I/O and Memory ........................................................................................15
3.4.2 Using a Combo Card as SDIO only or SD Memory only after Combo Initialization ..............15
3.4.3 Acceptable Commands after Initialization .............................................................................15
