SDI Technologies SDIO Card manual Special Initialization considerations for Combo Cards

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©Copyright 2000-2007 SD Card Association

SDIO Simplified Specification Version 2.00

Once an SDIO card has received a CMD5, the I/O portion of that card is enabled to respond normally to all further commands. This I/O enable of the functions within the I/O card shall remain set until a reset, power cycle or CMD52 with write to I/O reset is received by the card. Note that a SD memory only card may respond to a CMD5. The proper response for a memory only card would be Memory Present = 1 and Number of I/O Functions = 0. A memory only card built to SD Memory Card specification version 1.01 would detect the CMD5 as an illegal command and not respond. Note that unlike the similar memory command ACMD41, The SPI response to CMD5 does contain the OCR value from the card.

The I/O aware host sends CMD5. If the card responds with response R4 within the timeout value of Ncr as defined in the SD Physical Specification, the host determines the card’s configuration based on the data contained within the R4.

3.4Special Initialization considerations for Combo Cards

The host must be aware of some special situations when initializing a Combo card (SDIO plus SD Memory on the same card). This is caused because an implementation of the Combo card could actually use 2 separate controllers (Memory and I/O) in the same package and sharing the same bus lines. It important for the host to both detect and properly configure both parts (controllers) of a Combo card in order to prevent conflicts between the SDIO and the SD memory controller. These concerns are caused due to the different response to a reset (hard or soft) by the two controllers. Another concern is the value of the RCA (Relative Card Address) that exists within the Memory controller.

Note that this consideration is for the SD 1-bit and SD 4-bit modes only. In The SPI mode, card select/de-select is accomplished using the hardware CS line rather than the RCA.

3.4.1Re-initialize both I/O and Memory

When the host re-initializes both I/O and Memory controllers, it is strongly recommended that the host either execute a power reset (power off then on) or issues a reset commands to both controllers prior to any other operation. If the host chooses to use the reset commands, it shall issue CMD52 (I/O Reset) first, because it cannot issue CMD52 after CMD0 (see 4.4). After the reset, the host shall re-initialize both the I/O and Memory controller as defined in Figure 3-2.

3.4.2Using a Combo Card as SDIO only or SD Memory only after Combo Initialization

If a host intends to use only the SDIO or the Memory portion of a Combo Card, it is strongly recommended that the host power reset (power off then on) or issues reset commands to both controllers prior to any other operation. If the host chooses to use the reset commands, it shall issue CMD52 (I/O Reset) first, because it cannot issue CMD52 after CMD0 (see 4.4). After the resets, the host re-initializes either the I/O and Memory controller as defined in Figure 3-2.

3.4.3Acceptable Commands after Initialization

When the host re-initializes a Combo card, the acceptable commands that the host can issue are restricted until the I/O controller is placed into the command state and memory controller enters the transfer state. The kinds of prohibited commands are identified in the next section. Combo cards may not work correctly when the host issues these prohibited commands. The proper command sequence for the I/O controller and the memory controller are shown below. Note that CMD15 (GO_INACTIVE_STATE) can be sent at any time after initialization in order to send any addressed memory controller to the inactive state.

3.4.4Recommendations for RCA after Reset

Important Note: The RCA specification was not fully defined in SDIO Specification Ver1.0. There are two types of card (SDIO or Combo) with different responses to CMD0 or SDIO reset. The possible responses are:

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Contents SD Specifications Part E1 Sdio Simplified Specification Sdio Simplified Specification Version Changes compared to previous issueDate Version Release of SD Simplified Specification Conventions Used in This Document Table of Contents SPI and SD 1-bit Mode Interrupts 16.2 Table of Tables Table of Figures General Description Sdio FeaturesPrimary Reference Document Standard Sdio FunctionsSdio Card Types Sdio Signaling DefinitionSdio Card modes Sdio Host ModesSignal connection to two 4-bit Sdio cards Signal PinsReset Sdio Card InitializationDifferences in I/O card Initialization Sdio Simplified Specification Version MEM=0 Card initialization flow in SD mode Sdio aware host Illegal Command F8=0 Card initialization flow in SPI mode Sdio aware host VDD Voltage Window Position Iosendopcond Command CMD5OCR Values for CMD5 OCR bitIosendopcond Response R4 Response R4 in SD modeRecommendations for RCA after Reset Acceptable Commands after InitializationSpecial Initialization considerations for Combo Cards Re-initialize both I/O and MemoryRe-Initialization Flow for Memory controller Re-Initialization Flow for I/O ControllerEnabling CRC in SPI Combo Card Differences with SD Memory Specification Sdio Command ListUnsupported SD Memory Commands Reset for Sdio Modified R6 ResponseBus Width Timings Card Detect ResistorCombo Card 4-bit Control Card Detect Resistor StatesData Transfer Abort Data Transfer Block SizesChanges to SD Memory Fixed Registers Read AbortCID Register OCR RegisterCSD Register RCA RegisterSdio Status Register Structure ClearBit Identifier Type Value Description Iorwdirect Command CMD52 New I/O Read/Write CommandsIllegalcommand ComcrcerrorIorwdirect Response R5 1 CMD52 Response SD modesIdentifier Type Value Description Clear Condition DIS=DisabledCMD=DAT lines free TRN=TransferIorw Extended command Op Code Definition Iorwextended Command CMD53OP code Command operation CRC1 CMD53 Data Transfer Format Byte Count ValuesSdio Card Internal Operation Register Access TimeOverview InterruptsRead Wait Suspend/ResumeCMD52 During Data Transfer Sdio Fixed Internal MapCard Common Control Registers Cccr Common I/O Area CIAType Card Common Control Registers CccrCCCR/SDIO IOE3To abort transfers to/from memory Scsi 4BLS Transaction of function 0 CIA Empc Cccr bit DefinitionsAddress Function Basic Registers FBRFunction Basic Information Registers FBR Field TypeFBR bit and field definitions Sdio Simplified Specification Version Field TypeCard Information Structure CIS Setting Block Size with CMD53Multiple Function Sdio Cards Card Information Structure CIS and reserved area of CIAState Diagram for Bus State Machine Bus State DiagramCSA Access Embedded I/O Code Storage Area CSACSA Data Format Interrupt Timing Sdio InterruptsInterrupt Clear Timing Terminated Data Transfer Interrupt CycleSdio Suspend/Resume Operation Sdio Read Wait Operation Power Control Overview Power ControlPower Control support for Sdio Cards Master Power ControlPower Selection Power Control Support for the Sdio HostHigh-Power Tuples Reference Tuples by Master Power Control and Power SelectPower Control Operation High-Speed Mode Sdio High-Speed ModeSwitching Bus Speed Mode in a Combo Card Sdio Physical Properties Sdio PowerSdio Simplified Specification Version Inrush Current Limiting CIS Reference Document CIS FormatsBasic Tuple Format and Tuple Chain Structure Byte Order Within TuplesSdio Card Metaformat Tuple VersionTuples Supported by Sdio Cards Code Name DescriptionSdio Specific Extensions Cistplmanfid Manufacturer Identification String TupleCistplmanfid Manufacturer Identification Tuple Cistplfuncid Function Identification TupleCistplfunce Tuple General Structure Cistplfunce Function Extension TupleCistplfunce Tuple for Function 0 common Tplfidfunction Tuple for Function 0 commonCistplfunce Tuple for Function Tplfidfunction Tuple for FunctionByte Sdio Simplified Specification Version 10 Tplfefunctioninfo Definition Tplfidfunction Field Descriptions for Functions11 Tplfecsaproperty Definition Bit Name12 Cistplsdiostd Tuple Reserved for Sdio Cards Cistplsdiostd Function is a Standard Sdio FunctionCistplsdioext Tuple Reserved for Sdio Cards 13 Cistplsdioext Tuple Reserved for Sdio CardsSD and SPI Command List Table A-14 SD Mode Command ListNormative Sdmem Sdio Table A-15 SPI Mode Command ListNormative References Appendix BAbbreviations and Terms Appendix CLOW, High Informative
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