SDI Technologies SDIO Card manual Power Control Overview, Power Control support for Sdio Cards

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©Copyright 2000-2007 SD Card Association

SDIO Simplified Specification Version 2.00

11. Power Control

11.1Power Control Overview

The concept of high-power SDIO cards was introduced in Version 1.10 of the SDIO Specification. Power Control supports following two features:

•High-Power Support

SDIO cards created prior to Version 1.10 of the SDIO Specification were limited to a maximum current of 200mA at any time, irrespective of the number or types of functions supported. With the creation of wireless communication devices in the SDIO form factor, a need was seen to provide more current to accommodate the higher power requirements of some SDIO cards. Since backward compatibility is a primary concern for any changes made to this specification, a method was chosen to prevent a high-power card from drawing excessive amounts of current from hosts designed to only support the SDIO 1.0 cards. Master Power Control allows standard and high-power cards to be inserted into any host without causing excessive current damage to the host. It is important to note that there exists the possibility of trying to use a card that requires high-power in a standard power host and having that card fail to operate. Master Power Control is supported on a per card basis and available to the host in the CCCR. A high-power card may have a mix of both high and standard power functions.

•Power Selection Support

Not all hosts can supply enough current for all SDIO cards. A host may choose to use the SDIO card in a lower power mode to increase operation time. Power Selection enables the host to switch the card to a lower power mode. It is important to note that there exists the possibility of trying to use a standard power card in a host that does not have enough power to meet the card’s requirement. In this case the card will fail to operate. Cards supporting Power Selection will enable the widest range of host support. Power Selection is supported on a per function basis and available to the host in the FBR.

11.2Power Control support for SDIO Cards

11.2.1Master Power Control

SDIO version 1.10 cards indicate their support for the new power control functions with the SMPC (Support Master Power Control) bit in the CCCR (See section 6.9). Hosts enable the card’s power control functions with the EMPC (Enable Master Power Control) bit.

SMPC can be set to 0 if the card maximum current is less than 200mA and Power Selection (see section 11.2.2) is not supported. A SDIO version 1.10 card which has SMPC set to 1 shall maintain backward compatibility when EMPC is set to 0. A SDIO version 1.0 host may not be aware of EMPC, which will remain 0 (its default state).

In the case where EMPC is set to 0, the card total current shall not exceed 200mA. Functions that exceed 200mA shall not set IORx to 1 and TPLFE_OP_MAX_PWR shall be set to 0. If a multi-function card’s total power exceeds 200mA the card shall not set all IORx to 1, even if all IOEx are set to 1. Some of the functions’ IORx can be set to 1 as long as the card’s total current is less than 200mA. If the host tries to enable a function (IOEx =1) that will cause the card’s total current to exceed 200mA, the card shall disable (IORx=0) one or more functions to keep the card’s total current less than 200mA. Which functions are enabled depends on the design of the card vendor.

In the case where EMPC is set to 1, the card current can exceed 200mA, up to a maximum of 500mA. Card should be designed, where possible, to not require the maximum current , thus functioning in as many hosts as possible with sufficient power.

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Contents SD Specifications Part E1 Sdio Simplified Specification Date Version Sdio Simplified Specification VersionChanges compared to previous issue 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 PinsDifferences in I/O card Initialization ResetSdio 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 Unsupported SD Memory Commands Differences with SD Memory SpecificationSdio Command List Bus Width Reset for SdioModified R6 Response 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 RegisterBit Identifier Type Value Description Sdio Status Register StructureClear 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 Data Format CSA AccessEmbedded I/O Code Storage Area CSA 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 Switching Bus Speed Mode in a Combo Card High-Speed ModeSdio High-Speed Mode 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 commonByte Cistplfunce Tuple for FunctionTplfidfunction Tuple for Function 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 CardsNormative SD and SPI Command ListTable A-14 SD Mode Command List Sdmem Sdio Table A-15 SPI Mode Command ListNormative References Appendix BAbbreviations and Terms Appendix CLOW, High Informative
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