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<concept id="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B" xml:lang="en"><title>Platform

Specific Layer Implementation</title><shortdesc>Describes how to implement the Platform Specific Layer of the MMC

Controller. </shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>

<section id="GUID-4C6CA873-A798-5C79-8838-0CC3C9E914FB"><title>DMMCStack derived

class</title> <p>This class controls access to the MultiMediaCard stack. This

class has a number of pure virtual functions that need to be implemented in

your Variant DLL. The diagram at <xref href="GUID-BE6AFD38-5952-537F-848C-C76C8F5FA9BF.dita#GUID-BE6AFD38-5952-537F-848C-C76C8F5FA9BF/GUID-92F5EBE4-C9AD-5D9A-A80E-9AFD1A09B6B3">MultiMediaCard

controller basic structure</xref> shows the class in context. </p> <p>There

is one virtual function with a default implementation that needs to be overridden. </p> <ul>

<li id="GUID-01ABEA80-002F-5490-B90F-3AE83927220B"><p> <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-0B55A650-E9ED-56CB-B06F-B1113ACDF282">Init()</xref>  </p> </li>

<li id="GUID-04245FCC-D55A-5840-98CC-2113E7B6D9E4"><p> <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-CEF0EDF7-4B33-5452-8635-51C5319F78AE">MachineInfo()</xref> </p> </li>

<li id="GUID-C5C86175-9100-5687-96EB-F4AEAF0CE161"><p> <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-F41EA0A6-1CBF-5AE2-9C66-DD6E3B7312E0">ProgramPeriodInMilliSeconds()</xref>  </p> </li>

<li id="GUID-12B3B751-9EFE-5273-844B-A18D99E2A7FF"><p> <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-A7EC6536-3822-58C8-9A65-B71FDDBA10F3">AdjustPartialRead()</xref> </p> </li>

<li id="GUID-AF40CF60-918D-5D9D-96C3-D96FDAD94B85"><p> <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-8A3E9782-C8D4-562D-9470-5CCE0ED1C303">GetBufferInfo()</xref> </p> </li>

<li id="GUID-60AC1F94-4936-5AB1-B31E-CEDBDE59E08E"><p> <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-BC742EB6-7063-5D00-B422-96B3772605D5">SetBusConfigDefaults()</xref> </p> </li>

<li id="GUID-592CDEF6-F450-572A-878E-077ED633C621"><p> <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-49DF2E60-AE31-502E-B7CB-694AFAF69F1B">InitClockOff()</xref>  </p> </li>

<li id="GUID-82080A27-BCB7-5EC3-8F3E-2C1CDEDCA601"><p> <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-0DF60D11-AAD6-59E2-AE81-16E0DF96291B">ASSPDisengage()</xref> </p> </li>

<li id="GUID-5E0E9EC9-742A-5265-9429-C52B60D83863"><p> <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-99AC4F3B-E273-515E-8690-983E98E17256">ASSPReset()</xref> </p> </li>

<li id="GUID-DA38EA59-0A91-5498-9B3A-1F17D4511EFC"><p> <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-6EEE7EF6-4272-5116-BCEF-A852BB7B8FBD">CardDetect()</xref> </p> </li>

<li id="GUID-9F025A5A-F303-55C8-85C4-BAC0BF0C27E4"><p> <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-3F34865D-5B16-5F53-AF9E-9F52DB5D0FB5">WriteProtected()</xref> </p> </li>

<li id="GUID-D1B3A73F-E3AC-55C6-84E4-11A2AA9C3A7F"><p> <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-65547330-E112-55F2-AD4A-9B9CA5617E33">DoPowerDown()</xref> </p> </li>

<li id="GUID-4117DD14-59D4-5257-AAAD-79498391979E"><p> <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-C8C15101-4614-5DEC-A620-6EAE8EC463ED">DoPowerUpSM()</xref> </p> </li>

<li id="GUID-D93B8DEC-CFA0-5FC9-AF46-81A3B21F3545"><p> <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-C976320E-80FF-50F8-A882-F89C74F76ED3">InitClockOnSM()</xref> </p> </li>

<li id="GUID-F6BB7D3C-8A9A-5228-88ED-2F28980373D8"><p> <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-FABAED76-FC63-577B-9436-DC7C8978E2AE">IssueMMCCommandSM()</xref>  </p> </li>

</ul> <p id="GUID-0B55A650-E9ED-56CB-B06F-B1113ACDF282"><b>Init()</b> </p> <p> <xref href="GUID-B5193656-9819-3E00-A335-EEF1726115A5.dita#GUID-B5193656-9819-3E00-A335-EEF1726115A5/GUID-43A06EF7-FA7B-3653-97B4-B04336E3EB54"><apiname>DMMCStack::Init()</apiname></xref>  </p> <p>The

function is intended to initialise the stack, and is called during initialisation

of the MultiMediaCard controller Variant DLL from <xref href="GUID-45B97680-1756-3559-8A2D-2F2E851AD6A7.dita#GUID-45B97680-1756-3559-8A2D-2F2E851AD6A7/GUID-18825E56-F155-38D0-A4DF-A7C57D73C1EF"><apiname>DMMCSocket::Init()</apiname></xref>: </p> <p>You

will almost certainly need to provide your own implementation to perform any

platform-specific MultiMediaCard stack initialisation. Whatever your implementation

provides, <i>it is important that you call the base class function from within

your derived version</i>. </p> <p>Return <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref> if initialisation

is successful, otherwise return one of the system-wide error codes to indicate

initialisation failure. Note that returning a value other than <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref> will

cause the kernel to panic and to fail to boot. </p> <p>You will allocate a

data transfer buffer here. The MultiMediaCard media driver needs a memory

buffer to perform data transfer operations. Where supported, DMA is generally

used to do this, and requires physically contiguous memory. However, the media

driver is created each time a card is inserted into a machine and destroyed

when the card is removed, and giving the media driver the responsibility for

allocating the memory buffer means that it might not always be possible to

allocate physically contiguous pages for it as memory becomes fragmented over

time. </p> <p>The MultiMediaCard media driver uses the <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-8A3E9782-C8D4-562D-9470-5CCE0ED1C303">GetBufferInfo()</xref> function each time it is created to get a pointer

to the buffer, and to get its length. </p> <p>Although the MultiMediaCard

media driver only expects a single buffer, it actually uses this as two separate

buffers: </p> <ul>

<li id="GUID-21E69407-DEB2-5DBE-9614-ADFF7DBF06B6"><p>a minor buffer which

must have at least enough space for the MBR (512 bytes) </p> </li>

<li id="GUID-1FF25456-0CE3-582C-9FEC-B5913C1E437A"><p>a cache buffer to cache

data blocks from the card. </p> </li>

</ul> <p>The ideal size of the cache buffer depends on the characteristics

of the card present at the time, and it is possible to customise the MultiMediaCard

controller at the platform specific layer for a particular card. </p> <p>The

following example code allocates a physically contiguous buffer - a minor

buffer size of one block is allocated together with a cache buffer size of

eight blocks. The whole buffer is then rounded up to a whole number of memory

pages. </p> <codeblock id="GUID-B01B50BE-6574-5A81-BA25-8FDFEB2C5620" xml:space="preserve">// The constant calculations could be explicitly folded, but this illustrates

// how the values are derived.

const TUint blkSzLog2 = 9;                    

const TUint blkSz = 1 << blkSzLog2;

const TInt minorBufLen = Max(KDiskSectorSize, blkSz);

const TInt KMinBlocksInBuffer = 8;

const TInt cchBufLen = KMinBlocksInBuffer << blkSzLog2;

TInt totalBufLen = minorBufLen + cchBufLen;

// Allocate contiguous physical memory

totalBufLen = Kern::RoundToPageSize(totalBufLen);

TPhysAddr physAddr = 0;

r = Epoc::AllocPhysicalRam(totalBufLen, physAddr);

__KTRACE_OPT(KHARDWARE, Kern::Printf("mmc:ini:physical = %08x", physAddr));

if (r != KErrNone)

    {

    return r;

    }

DPlatChunkHw* bufChunk = NULL;

r = DPlatChunkHw::New(bufChunk, physAddr, totalBufLen, EMapAttrCachedWBRA|EMapAttrSupRw);

if(r != KErrNone)

    {

    if (physAddr)

        {

        Epoc::FreePhysicalRam(physAddr, totalBufLen);

        }

    return r;

    }

iMDBuf = reinterpret_cast<TUint8*>(bufChunk->LinearAddress());

iMDBufLen = totalBufLen;

</codeblock> <p id="GUID-CEF0EDF7-4B33-5452-8635-51C5319F78AE"><b>MachineInfo()</b> </p> <p> <xref href="GUID-B5193656-9819-3E00-A335-EEF1726115A5.dita#GUID-B5193656-9819-3E00-A335-EEF1726115A5/GUID-3E5532A5-4645-3F77-A7A9-7AFF334FA5A4"><apiname>DMMCStack::MachineInfo()</apiname></xref>  </p> <p>The

function returns configuration information for the MultiMediaCard stack. </p> <p>The

function takes a reference to a <xref href="GUID-3F9D89E8-44F0-35B3-9404-6CCAC79763E8.dita"><apiname>TMMCMachineInfo</apiname></xref> object,

and your implementation must fill the public data members of the object. </p> <p id="GUID-F41EA0A6-1CBF-5AE2-9C66-DD6E3B7312E0"><b>ProgramPeriodInMilliSeconds()</b> </p> <p> <xref href="GUID-B5193656-9819-3E00-A335-EEF1726115A5.dita#GUID-B5193656-9819-3E00-A335-EEF1726115A5/GUID-C0998F1F-EE3B-32C1-9898-288EA1D71AC0"><apiname>DMMCStack::ProgramPeriodInMilliSeconds()</apiname></xref>  </p> <p>When a data block is written to a card, the data is read into an

internal buffer on the card and is then programmed into the payload memory.

While the card is in <i>programming mode</i>, it cannot be read from, or written

to, but it is possible to query its status using CMD13. </p> <p>Immediately

after a block of data is written by <codeph>CIMReadWriteBlocksSM()</codeph>,

the MultiMediaCard controller requests the card's state using CMD13. If the

card is still in the programming state, then the state machine <codeph>ProgramTimerSM()</codeph> launches

a timer with the period returned by <codeph>ProgramPeriodInMilliSeconds()</codeph>.

The state of the card is periodically checked until it is no longer in programming

mode. </p> <p>For platforms that do not provide an interrupt to indicate when

programming mode is finished, <codeph>ProgramPeriodInMilliSeconds()</codeph> should

return the interval, in milliseconds, to be used by the poll timer. </p> <p id="GUID-A7EC6536-3822-58C8-9A65-B71FDDBA10F3"><b>AdjustPartialRead()</b> </p> <p> <xref href="GUID-B5193656-9819-3E00-A335-EEF1726115A5.dita#GUID-B5193656-9819-3E00-A335-EEF1726115A5/GUID-7FEC1574-5448-3DF5-8BD2-AABDBD0211C3"><apiname>DMMCStack::AdjustPartialRead()</apiname></xref>  </p> <p>Some

cards support a partial read feature, which is indicated by the <codeph>READ_BL_PARTIAL</codeph> bit

in the <codeph>CSD</codeph> register. When this is the case, it is possible

to read a section within a single physical block, without having to read the

entire block. </p> <p>The MultiMediaCard media driver uses this feature to

read small amounts of data more quickly. However, many hardware implementations

impose restrictions on the granularity of the data that can be read from the

card. For example, they may use a 32-bit FIFO. </p> <p>This function allows

you to enforce the limits imposed by the hardware. </p> <p>The <codeph>aStart</codeph> and <codeph>aEnd</codeph> arguments

of <codeph>AdjustPartialRead()</codeph> define the range on the card from

which the media driver would like to read. Your implementation should return

in <codeph>*aPhysStart</codeph> and <codeph>*aPhysEnd</codeph> the range that

the hardware will allow to be read. </p> <p>For example, to word align data,

the function would be implemented using the following code: </p> <codeblock id="GUID-30DE526C-70C2-5118-BFBB-72759EFC8C93" xml:space="preserve">void AdjustPartialRead(const TMMCard* aCard, TUint32 aStart, TUint32 aEnd, TUint32* aPhysStart, TUint32* aPhysEnd);

    {

    ...

    const TUint32 KWordMask = 3;

    *aPhysStart = aStart & ~KWordMask;

    *aPhysEnd = (aEnd + KWordMask) & ~KWordMask;

    ...

    }

</codeblock> <p id="GUID-8A3E9782-C8D4-562D-9470-5CCE0ED1C303"><b>GetBufferInfo()</b> </p> <p> <xref href="GUID-B5193656-9819-3E00-A335-EEF1726115A5.dita#GUID-B5193656-9819-3E00-A335-EEF1726115A5/GUID-EC9B740A-3A07-35AB-BACE-2EC1F96EEF0F"><apiname>DMMCStack::GetBufferInfo()</apiname></xref>  </p> <p>The

MultiMediaCard media driver needs a memory buffer to perform data transfer

operations, and this is, typically, allocated once only by the <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-0B55A650-E9ED-56CB-B06F-B1113ACDF282">Init()</xref> function when this stack object is initialised. </p> <p>The

MultiMediaCard media driver is created each time a card is inserted into a

machine and destroyed when the card is removed, and it uses this function,

each time it is created to get a pointer to the memory buffer, and to get

its length. The MultiMediaCard media driver then uses this buffer, over its

lifetime, for data transfer operations. </p> <p id="GUID-BC742EB6-7063-5D00-B422-96B3772605D5"><b>SetBusConfigDefaults()</b> </p> <p> <xref href="GUID-B5193656-9819-3E00-A335-EEF1726115A5.dita#GUID-B5193656-9819-3E00-A335-EEF1726115A5/GUID-C7297E13-5F78-396D-842B-FB16D3424374"><apiname>DMMCStack::SetBusConfigDefaults()</apiname></xref>  </p> <p>The function returns information about the MultiMediaCard bus configuration

for this platform. </p> <p>The function takes a <xref href="GUID-F9432D7B-41C9-3048-AC50-B5BCF8BE11D0.dita"><apiname>TUint</apiname></xref> value

containing the bus speed that the controller intends to use, and a reference

to a <xref href="GUID-C0E2780A-47B3-31A2-827C-AF89C1B65F2E.dita"><apiname>TMMCBusConfig</apiname></xref> object. The implementation of this function

must fill the public data members of this object. See the class reference

documentation for the data members. </p> <p> <xref href="GUID-B5193656-9819-3E00-A335-EEF1726115A5.dita"><apiname>DMMCStack</apiname></xref> has

two private data members of type <xref href="GUID-75FF770B-07D1-3C07-9577-5A37841E53E7.dita"><apiname>TMMCStackConfig</apiname></xref>: </p> <ul>

<li id="GUID-A56BF364-F02F-54EA-80F8-E4AB5E7A10C9"><p> <codeph>iMasterConfig</codeph>  </p> </li>

<li id="GUID-C94FFA4E-51C7-5CBA-BFBB-F692438412FE"><p> <codeph>iConfig</codeph>  </p> </li>

</ul> <p>The information returned by the call to <codeph>SetBusConfigDefaults()</codeph> is

stored in <codeph>iMasterConfig</codeph>'s <codeph>iBusConfig</codeph> private

data member. </p> <p> <codeph>iMasterConfig</codeph> contains the master bus

configuration settings for the platform. Each time a new session is made current,

the master bus configuration settings are merged with the specific bus configuration

settings for that session, (as set up in the public data member <xref href="GUID-0186BEDE-8E28-3F8C-8CAE-A8B92F41F47A.dita#GUID-0186BEDE-8E28-3F8C-8CAE-A8B92F41F47A/GUID-73BC8CE4-593E-3BAC-909A-FB8F419895C8"><apiname>DMMCSession::iConfig</apiname></xref>),

and the result is stored in <codeph>iConfig</codeph>. It is these merged bus

configuration settings that are used to configure the hardware interface.

The platform specific layer can access these settings with a call to Master<xref href="GUID-B5193656-9819-3E00-A335-EEF1726115A5.dita#GUID-B5193656-9819-3E00-A335-EEF1726115A5/GUID-E0275614-109E-3803-A0AE-3313E1E0038B"><apiname>DMMCStack::BusConfig()</apiname></xref>. </p> <p> <codeph> SetBusConfigDefaults()</codeph> is called at two stages in the execution of the macro CIM_UPDATE_ACQ to

update the <codeph>iMasterConfig</codeph> object. </p> <ul>

<li id="GUID-5C98DB8C-60AF-5333-A250-5D6509D754E5"><p>First, it is called

at the start of the card initialisation stage with the bus speed argument, <codeph>aClock</codeph>,

set to the fOD rate (400kHz). </p> </li>

<li id="GUID-0CD15184-15F8-5104-908F-612CCBCA953A"><p>Second, it is called

after the CSD registers for each card have been read with the bus speed argument, <codeph>aClock</codeph>,

set to the slowest maximum transfer rate (TRAN_SPEED) reported by any of the

CSD registers. </p> </li>

</ul> <p id="GUID-49DF2E60-AE31-502E-B7CB-694AFAF69F1B"><b> InitClockOff()</b> </p> <p> <xref href="GUID-B5193656-9819-3E00-A335-EEF1726115A5.dita#GUID-B5193656-9819-3E00-A335-EEF1726115A5/GUID-BF94B298-7F72-33F7-A2F0-F19807BF2CDC"><apiname>DMMCStack::InitClockOff()</apiname></xref>  </p> <p>Switches

from identification mode of operation to data transfer mode operation. </p> <p>When

this function is called, the clock information in the <codeph>iBusConfig</codeph> member

(see <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-BC742EB6-7063-5D00-B422-96B3772605D5">SetBusConfigDefaults()</xref>)

will not have been updated to the new data transfer rate. </p> <p>This function

should, in general, just switch from open drain to push-pull bus mode, with

the clock rate being changed at the start of <xref href="GUID-B5193656-9819-3E00-A335-EEF1726115A5.dita#GUID-B5193656-9819-3E00-A335-EEF1726115A5/GUID-A48C1C16-B465-3DDA-9C83-00DEB8D27B68"><apiname>DMMCStack::IssueMMCCommandSM()</apiname></xref>,

when <codeph>iBusConfig</codeph> will be valid. </p> <p id="GUID-0DF60D11-AAD6-59E2-AE81-16E0DF96291B"><b> ASSPDisengage()</b> </p> <p> <xref href="GUID-B5193656-9819-3E00-A335-EEF1726115A5.dita#GUID-B5193656-9819-3E00-A335-EEF1726115A5/GUID-36C720F9-DEAF-3896-A12A-2AE2581AA347"><apiname>DMMCStack::ASSPDisengage()</apiname></xref>  </p> <p>This

function is called by the platform independent layer each time a session has

completed or has been aborted. </p> <p>The function gives the platform specific

layer the chance to free resources or disable any activities that were required

to perform the session. </p> <p>The implementation should not turn off the

clock to the hardware interface as this will be turned off by the inactivity

timer. Typically, the implementation disables DMA and interface interrupts,

and forces the hardware interface into idle. </p> <p>At the end of your implementation,

you must add a call <xref href="GUID-B5193656-9819-3E00-A335-EEF1726115A5.dita#GUID-B5193656-9819-3E00-A335-EEF1726115A5/GUID-3DFCBE96-E9F3-3FF3-97BC-A3A3024089BD"><apiname>DMMCStack::ReportASSPDisengaged()</apiname></xref> to

report to the platform independent layer that platform specific layer resources

have been disengaged. </p> <p id="GUID-99AC4F3B-E273-515E-8690-983E98E17256"><b>ASSPReset()</b> </p> <p> <xref href="GUID-B5193656-9819-3E00-A335-EEF1726115A5.dita#GUID-B5193656-9819-3E00-A335-EEF1726115A5/GUID-36D3F4D9-A2FC-3355-ABE0-31C9F7397E2D"><apiname>DMMCStack::ASSPReset()</apiname></xref>  </p> <p>This

function is called by the platform independent layer when the current session

is being aborted, and platform specific asynchronous activity is to be cancelled.

The function may also be called by the platform specific layer as part of

the <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-65547330-E112-55F2-AD4A-9B9CA5617E33">DoPowerDown()</xref> implementation. </p> <p>The function gives the platform specific layer the chance to stop all activities

on the host stack. It will, in general, perform the same operations as <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-0DF60D11-AAD6-59E2-AE81-16E0DF96291B">ASSPDisengage()</xref> but,

in addition, will turn off the clock to the hardware interface and release

any requested power requirements made on the power model, i.e. release any

power requirements made by <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-C976320E-80FF-50F8-A882-F89C74F76ED3">InitClockOnSM()</xref>. </p> <p>At the end of your implementation, you must add a call <xref href="GUID-B5193656-9819-3E00-A335-EEF1726115A5.dita#GUID-B5193656-9819-3E00-A335-EEF1726115A5/GUID-3DFCBE96-E9F3-3FF3-97BC-A3A3024089BD"><apiname>DMMCStack::ReportASSPDisengaged()</apiname></xref> to

report to the platform independent layer that platform specific layer resources

have been disengaged. </p> <p id="GUID-6EEE7EF6-4272-5116-BCEF-A852BB7B8FBD"><b>CardDetect()</b> </p> <p> <xref href="GUID-B5193656-9819-3E00-A335-EEF1726115A5.dita#GUID-B5193656-9819-3E00-A335-EEF1726115A5/GUID-02C4D1A0-6149-389D-9F31-3E7EBF1DCA66"><apiname>DMMCStack::CardDetect()</apiname></xref>  </p> <p>Implement

this function to report whether a card is present in a specified card socket. </p> <p>This

function takes a TUint value containing the card socket that is to be queried. </p> <p id="GUID-3F34865D-5B16-5F53-AF9E-9F52DB5D0FB5"><b>WriteProtected()</b> </p> <p> <xref href="GUID-B5193656-9819-3E00-A335-EEF1726115A5.dita#GUID-B5193656-9819-3E00-A335-EEF1726115A5/GUID-E7E97501-10E7-38E6-9F8C-2A62F260BA46"><apiname>DMMCStack::WriteProtected()</apiname></xref>  </p> <p>Implement

this function to report whether a card in a specified card socket is mechanically

write protected. </p> <p>This function takes a TUint value containing the

card socket that is to be queried. </p> <p id="GUID-65547330-E112-55F2-AD4A-9B9CA5617E33"><b>DoPowerDown()</b> </p> <p> <xref href="GUID-B5193656-9819-3E00-A335-EEF1726115A5.dita#GUID-B5193656-9819-3E00-A335-EEF1726115A5/GUID-3E90AF73-F4D3-34C5-B6D3-6BF69C6137C8"><apiname>DMMCStack::DoPowerDown()</apiname></xref>  </p> <p>This

function is called as part of the bus power down sequence: </p> <ul>

<li id="GUID-E9E072D3-A2F7-5DD2-B7D9-A89840BBA914"><p>by the power model,

in power standby and power emergency standby situations </p> </li>

<li id="GUID-1EFB0616-45B9-5EC2-9456-54F7D10D2894"><p>when a door-open event

occurs </p> </li>

<li id="GUID-83F42DEB-C6EE-5558-8907-CFD141461456"><p>when the bus inactivity

timer has timed out </p> </li>

<li id="GUID-0EA77E57-E2D0-599D-8E90-ECE1D21BC329"><p>if a power supply unit

(PSU) voltage check fails. </p> </li>

</ul> <p>The function should stop all activities on the host stack, turn off

the clock to the hardware interface and release any requested power requirements

made on the power model. The function is very often implemented as a call

of <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-99AC4F3B-E273-515E-8690-983E98E17256">ASSPReset()</xref>. </p> <p>The

function should not turn off the MultiMediaCard power supply unit as this

will be performed immediately afterwards by a call to the <xref href="GUID-FBCEFDB6-28FF-3201-8E13-F12E3759E36B.dita#GUID-FBCEFDB6-28FF-3201-8E13-F12E3759E36B/GUID-4DF0741F-B143-3B46-82BE-9CD0261C27E5"><apiname>DMMCPsu::DoSetState()</apiname></xref> derived

class function from the platform independent layer. </p> <p id="GUID-C8C15101-4614-5DEC-A620-6EAE8EC463ED"><b> DoPowerUpSM()</b> </p> <p> <xref href="GUID-B5193656-9819-3E00-A335-EEF1726115A5.dita#GUID-B5193656-9819-3E00-A335-EEF1726115A5/GUID-791BCA03-61F3-3C1C-BA2D-D633A94AF299"><apiname>DMMCStack::DoPowerUpSM()</apiname></xref>  </p> <p>This

is a state machine function, called as a child function at the start of the

CIM_UPDATE_ACQ macro state machine. </p> <p>The function should perform the

necessary platform specific actions associated with powering up the bus. This

includes turning on the MultiMediaCard PSU. However, the hardware interface

clock should <i>not</i> be turned on as part of this function. </p> <p>If

the controller has to request power resources from the power model, e.g. where

a fast system clock is required all the time the bus is powered, then this

state machine function can be used to wait asynchronously for this resource

to become available. </p> <p>If the activity performed by this function completes

successfully: </p> <ul>

<li id="GUID-7C64DB32-139B-5F45-9F2C-6693F9E16F83"><p>it must call <xref href="GUID-B5193656-9819-3E00-A335-EEF1726115A5.dita#GUID-B5193656-9819-3E00-A335-EEF1726115A5/GUID-40973A35-3A73-3DBD-9EB7-99CE55E6D694"><apiname>DMMCStack::ReportPowerUp()</apiname></xref>. </p> </li>

<li id="GUID-42E872B5-EA6A-5901-AD93-5F9B99C81D69"><p>it returns <xref href="GUID-E7D46003-E502-39D1-AF52-83B87AE6930B.dita"><apiname>KMMCErrNone</apiname></xref>. </p> </li>

</ul> <p>The function should return <xref href="GUID-E7D46003-E502-39D1-AF52-83B87AE6930B.dita"><apiname>KMMCErrNone</apiname></xref> if it completes

successfully or one of the other <xref href="GUID-FF4AB1CF-7A2C-3FC6-B123-D6819E1BCDCA.dita"><apiname>TMMCErr</apiname></xref> error codes. </p> <p>See

the general background information on <xref href="GUID-80E0DB93-A96A-54A8-A201-E11935418BE7.dita">the

state machine</xref>. </p> <p id="GUID-C976320E-80FF-50F8-A882-F89C74F76ED3"><b>InitClockOnSM()</b> </p> <p> <xref href="GUID-B5193656-9819-3E00-A335-EEF1726115A5.dita#GUID-B5193656-9819-3E00-A335-EEF1726115A5/GUID-7B91EF52-26E5-333C-A037-B142B492BCC4"><apiname>DMMCStack::InitClockOnSM()</apiname></xref>  </p> <p>This

is a state machine function, called as part of the CIM_UPDATE_ACQ macro state

machine. </p> <p>The function should turn on the clock to the hardware interface.

The function is so named because this clock is always first turned on at the

identification mode frequency. </p> <p>The function is implemented as a state

machine function because it may be necessary to include a short delay after

the clock has been turned on to allow it to stabilise. </p> <p>If it is necessary

for the MultiMediaCard controller to request any power resources from the

power model on this platform, for example, requesting a necessary system clock,

then it should be performed as part of this function. In some cases, it may

be necessary to wait for this power resource to become available. </p> <p>At

the <i>beginning</i> of your implementation, you must add a call <xref href="GUID-B5193656-9819-3E00-A335-EEF1726115A5.dita#GUID-B5193656-9819-3E00-A335-EEF1726115A5/GUID-D797747A-0AF6-36B1-BD92-3D6950A3B7B4"><apiname>DMMCStack::ReportASSPEngaged()</apiname></xref> to

report to the platform independent layer that platform specific layer resources

have been engaged. </p> <p>The function should return <xref href="GUID-E7D46003-E502-39D1-AF52-83B87AE6930B.dita"><apiname>KMMCErrNone</apiname></xref> if

it completes successfully or one of the other <xref href="GUID-FF4AB1CF-7A2C-3FC6-B123-D6819E1BCDCA.dita"><apiname>TMMCErr</apiname></xref> error

codes. </p> <p>Note: </p> <ul>

<li id="GUID-2474710D-C595-5331-9182-A2EF97A1EB27"><p>the function is only

called once for each invocation of the CIM_UPDATE_ACQ macro and the important

thing to stress is that the interface clock is being turned on after a period

when it has been off, and therefore often requires time to stabilise. </p> </li>

<li id="GUID-FE92334D-757D-5C08-AF98-9E0912BA2820"><p>In the course of executing

a session, the MultiMediaCard controller may switch the clock more than once

between the identification mode frequency and the data transfer mode frequency,

but this function only ever gets called once. </p> </li>

</ul> <p>See the general background information on <xref href="GUID-80E0DB93-A96A-54A8-A201-E11935418BE7.dita">the

state machine</xref>. </p> <p id="GUID-FABAED76-FC63-577B-9436-DC7C8978E2AE"><b> IssueMMCCommandSM()</b> </p> <p> <xref href="GUID-B5193656-9819-3E00-A335-EEF1726115A5.dita#GUID-B5193656-9819-3E00-A335-EEF1726115A5/GUID-A48C1C16-B465-3DDA-9C83-00DEB8D27B68"><apiname>DMMCStack::IssueMMCCommandSM()</apiname></xref>  </p> <p>This

is a <xref href="GUID-80E0DB93-A96A-54A8-A201-E11935418BE7.dita">state machine</xref> function

that executes a single command over the bus. The implementation of this function

is an important part in the process of porting the MultiMediaCard controller. </p> <p>The

input parameters for the command are passed via the current command descriptor,

an instance of the <xref href="GUID-6B3DDBFD-3A4A-3694-A058-7794700FEC7A.dita"><apiname>TMMCCommandDesc</apiname></xref> class, on the session’s

command stack. The parameters contain information such as: the type of command,

the response type, the command arguments, the data source/destination for

data transfer commands etc. Use <xref href="GUID-0186BEDE-8E28-3F8C-8CAE-A8B92F41F47A.dita#GUID-0186BEDE-8E28-3F8C-8CAE-A8B92F41F47A/GUID-931547BD-665D-326A-92B5-909B2D57F8C6"><apiname>DMMCSession::Command()</apiname></xref> to

get the current command descriptor. </p> <p>Information about the command

response, the number of bytes transferred etc., is passed back using the same

command descriptor. Specifically, the platform independent layer relies on

responses to the following commands being returned in the <xref href="GUID-6B3DDBFD-3A4A-3694-A058-7794700FEC7A.dita#GUID-6B3DDBFD-3A4A-3694-A058-7794700FEC7A/GUID-86553172-AE4E-3707-A0D2-8C2BB8880253"><apiname>TMMCCommandDesc::iResponse</apiname></xref> member,

in big-endian format: </p> <ul>

<li id="GUID-45605105-B91A-506B-A0F9-A317CA84D5EF"><p>Returns the OCR register

value in response to a SEND_OP_COND command (CMD1). Note that there is <i>no

CRC</i> with this response. Your code should ignore any CRC failure indication

from the MultiMediaCard controller hardware, and just copy the response into <xref href="GUID-6B3DDBFD-3A4A-3694-A058-7794700FEC7A.dita#GUID-6B3DDBFD-3A4A-3694-A058-7794700FEC7A/GUID-86553172-AE4E-3707-A0D2-8C2BB8880253"><apiname>TMMCCommandDesc::iResponse</apiname></xref>. </p> </li>

<li id="GUID-3E8B7D20-71F1-5609-8A16-24C6E2A7186A"><p>Returns the CID register

value in response to an ALL_SEND_CID command (CMD2) and a SEND_CID command

(CMD10). </p> </li>

<li id="GUID-8D051F10-65BB-57AF-8B75-247829DC239A"><p>Returns the CSD register

value in response to a SEND_CSD command (CMD9). </p> </li>

<li id="GUID-C899645F-8478-57BF-8E1E-58AC50EB9FE3"><p>Returns the card status

in response to all R1 and R1b commands. </p> </li>

</ul> <p>Note that you can use the functions <xref href="GUID-32036692-8BA3-3AAF-9FD8-D135DFADAE77.dita#GUID-32036692-8BA3-3AAF-9FD8-D135DFADAE77/GUID-D2EFC17B-FC2E-3FDC-AE7A-E2AA109D4B40"><apiname>TMMC::BigEndian4Bytes()</apiname></xref> and

TMC::to help with conversion to big-endian format. </p> <p>The function should

return <xref href="GUID-E7D46003-E502-39D1-AF52-83B87AE6930B.dita"><apiname>KMMCErrNone</apiname></xref> if it completes successfully or one

of the other <xref href="GUID-FF4AB1CF-7A2C-3FC6-B123-D6819E1BCDCA.dita"><apiname>TMMCErr</apiname></xref> error codes. </p> <p>See also background

information: </p> <ul>

<li id="GUID-0667980A-4A9E-5BD0-952E-97AD4C83B939"><p> <xref href="GUID-C059F39F-BC53-5C92-B05E-863B8CF22859.dita">Issuing

commands</xref>  </p> </li>

<li id="GUID-DF2B96DD-DD85-52C2-9EC8-30379E03D1DA"><p> <xref href="GUID-80E0DB93-A96A-54A8-A201-E11935418BE7.dita">The

state machine</xref>. </p> </li>

</ul> </section>

<section id="GUID-3A1E907E-A74D-59CB-A1D6-FEF4849EF2D5"><title>DMMCPsu derived

class</title> <p>This class controls the MultiMediaCard socket's power supply.

A class needs to be derived from this in the platform specific layer to handle

the Variant specific functionality of the power supply. </p> <p>This class

has a number of pure virtual functions that need to be implemented in your

Variant DLL. The diagram at <xref href="GUID-BE6AFD38-5952-537F-848C-C76C8F5FA9BF.dita#GUID-BE6AFD38-5952-537F-848C-C76C8F5FA9BF/GUID-92F5EBE4-C9AD-5D9A-A80E-9AFD1A09B6B3">MultiMediaCard

controller basic structure</xref> shows the class in context. </p> <p>There

is one virtual function with an empty default implementation that needs to

be overridden. </p> <ul>

<li id="GUID-025272EF-9DE8-5975-8993-006EE4D56E80"><p> <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-6EB8EF1C-BCCB-54A1-8CBA-4E8A2A20CABE">DoCreate()</xref>  </p> </li>

<li id="GUID-6BAFE3AA-6CCA-581B-A96C-D1FD89D1D8CD"><p> <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-99529E84-17E1-5F23-9A1B-EBE3976D9B14">PsuInfo()</xref>  </p> </li>

<li id="GUID-7419D681-D0CC-5CA7-8EE7-0D5A20779921"><p> <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-5809318D-E3E1-5261-AABA-604EBE72523F">DoSetState()</xref>  </p> </li>

<li id="GUID-E570E830-B57E-5A39-9EF1-CF68F3853AFF"><p> <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-B5030D2E-A466-596C-A2C3-73F38CF9C1A7">DoCheckVoltage()</xref>  </p> </li>

</ul> <p id="GUID-6EB8EF1C-BCCB-54A1-8CBA-4E8A2A20CABE"><b>DoCreate()</b> </p> <p> <xref href="GUID-FBCEFDB6-28FF-3201-8E13-F12E3759E36B.dita#GUID-FBCEFDB6-28FF-3201-8E13-F12E3759E36B/GUID-32771B9D-D2B8-33F5-AFC5-4476165C0A76"><apiname>DMMCPsu::DoCreate()</apiname></xref>  </p> <p>The

function is intended to perform hardware initialisation on the MultiMediaCard

power supply, for example, setting port direction registers. </p> <p>The function

is called after creation of the <xref href="GUID-FBCEFDB6-28FF-3201-8E13-F12E3759E36B.dita"><apiname>DMMCPsu</apiname></xref> derived class instance,

which is done during kernel initialisation when the MultiMediaCard controller

Variant DLL extension is loaded. </p> <p>The function has a default implementation

that just returns <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>. </p> <p>Your implementation

should <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref> if the hardware initialisation is successful,

otherwise it should return one of the system-wide error codes to indicate

initialisation failure. Note that returning a value other than <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref> will

cause the kernel to panic and to fail to boot. </p> <p id="GUID-99529E84-17E1-5F23-9A1B-EBE3976D9B14"><b>PsuInfo()</b> </p> <p> <xref href="GUID-FBCEFDB6-28FF-3201-8E13-F12E3759E36B.dita#GUID-FBCEFDB6-28FF-3201-8E13-F12E3759E36B/GUID-C7600EDA-B564-31E2-835C-9C580A29FC1D"><apiname>DMMCPsu::PsuInfo()</apiname></xref>  </p> <p>The

function returns information about the MultiMediaCard power supply. </p> <p>The

function takes a reference to a <xref href="GUID-E3BB783F-423F-352A-9B6E-FD23EC80AA8D.dita"><apiname>TPBusPsuInfo</apiname></xref> object, and

your implementation must fill the public data members of the object. </p> <p>Note: </p> <ul>

<li id="GUID-B8527FE4-61BB-574A-A200-5EA083A76A6D"><p>You can use the constant <xref href="GUID-3B63FFD6-AE21-366A-B435-AE6213AA2EE0.dita"><apiname>KMMCAdjustableOpVoltage</apiname></xref> to

set bit 31 in <xref href="GUID-E3BB783F-423F-352A-9B6E-FD23EC80AA8D.dita#GUID-E3BB783F-423F-352A-9B6E-FD23EC80AA8D/GUID-6B1E1CDD-A0E7-3AA5-989E-8D7A199ADE2A"><apiname>TPBusPsuInfo::iVoltageSupported</apiname></xref>. </p> </li>

<li id="GUID-694DB272-C66E-5392-8C7E-DC1B875E9DD3"><p>Set <xref href="GUID-E3BB783F-423F-352A-9B6E-FD23EC80AA8D.dita#GUID-E3BB783F-423F-352A-9B6E-FD23EC80AA8D/GUID-8C9792BC-8FAA-3DE5-8032-7546887FA8FB"><apiname>TPBusPsuInfo::iNotLockedTimeOut</apiname></xref> to

0. </p> </li>

</ul> <p id="GUID-5809318D-E3E1-5261-AABA-604EBE72523F"><b> DoSetState()</b> </p> <p> <xref href="GUID-FBCEFDB6-28FF-3201-8E13-F12E3759E36B.dita#GUID-FBCEFDB6-28FF-3201-8E13-F12E3759E36B/GUID-4DF0741F-B143-3B46-82BE-9CD0261C27E5"><apiname>DMMCPsu::DoSetState()</apiname></xref>  </p> <p>The

function is called to turn the PSU on or off. </p> <p>The requested state

of the PSU depends on the <xref href="GUID-CD00D507-CC86-33BE-91A7-FAF7EAFD4840.dita"><apiname>TPBusPsuState</apiname></xref> value passed to

it. </p> <p>If the PSU supports voltage adjustment, rather than a single fixed

value, then the required voltage setting is contained in the protected data

member <xref href="GUID-FBCEFDB6-28FF-3201-8E13-F12E3759E36B.dita#GUID-FBCEFDB6-28FF-3201-8E13-F12E3759E36B/GUID-7A625108-D5AE-301F-9CAB-2625DAD0C0B0"><apiname>DMMCPsu::iVoltageSetting</apiname></xref>. </p> <p>Note that the

stack may call this function to request the power to be turned on when it

is already on. You should check for this and do nothing if the power is already

in the requested state. </p> <p id="GUID-B5030D2E-A466-596C-A2C3-73F38CF9C1A7"><b>DoCheckVoltage()</b> </p> <p> <xref href="GUID-FBCEFDB6-28FF-3201-8E13-F12E3759E36B.dita#GUID-FBCEFDB6-28FF-3201-8E13-F12E3759E36B/GUID-17AC2A1C-5430-38B1-BD3F-966CE4936940"><apiname>DMMCPsu::DoCheckVoltage()</apiname></xref>  </p> <p>The

function is called to check that the voltage level of the PSU is as expected. </p> <p>Checking

the voltage level may be a long running operation (e.g. using an ADC), and

it may not always be appropriate to perform and complete the check directly

within this function. </p> <p>When voltage checking is complete, either synchronously

in this function, or asynchronously at some later stage, the result should

be returned by calling the base class function <xref href="GUID-A8B5FB5A-4709-3F29-B2CB-81FC5B0E7D63.dita#GUID-A8B5FB5A-4709-3F29-B2CB-81FC5B0E7D63/GUID-5643935F-9E97-35B0-9D92-88CA613F0016"><apiname>DPBusPsuBase::ReceiveVoltageCheckResult()</apiname></xref>.

Pass <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref> to indicate a successful check; pass <xref href="GUID-A94AC24A-EADF-3913-8345-708ED637968E.dita"><apiname>KErrGeneral</apiname></xref> to

indicate a failed check. </p> <p>Note that this function is not called as

part of <xref href="GUID-B5193656-9819-3E00-A335-EEF1726115A5.dita#GUID-B5193656-9819-3E00-A335-EEF1726115A5/GUID-791BCA03-61F3-3C1C-BA2D-D633A94AF299"><apiname>DMMCStack::DoPowerUpSM()</apiname></xref> processing, which means

that it is not possible to use this function to introduce a delay until power

is stable when the PSU is turned on. If such a delay is required while the

power lines stabilise, then it will be necessary to make this function part

of the DoPowerUpSM state machine. </p> </section>

<section id="GUID-C80E57B1-933B-55D7-949B-E68DB9B96B94"><title>DMMCMediaChange

derived class</title> <p>This class provides support for dealing with media

change events, i.e. the insertion and removal of removable media. </p> <p>A

class needs to be derived from this in the platform specific layer to handle

the Variant specific functionality. </p> <p>This class has a number of pure

virtual functions that need to be implemented in your Variant DLL. The diagram

at <xref href="GUID-BE6AFD38-5952-537F-848C-C76C8F5FA9BF.dita#GUID-BE6AFD38-5952-537F-848C-C76C8F5FA9BF/GUID-92F5EBE4-C9AD-5D9A-A80E-9AFD1A09B6B3">MultiMediaCard

controller basic structure</xref> shows the class in context. </p> <p>There

is one virtual function with an empty default implementation that needs to

be overridden. </p> <ul>

<li id="GUID-1BAEFE73-3B73-5BA7-872D-89C3B3F8BF75"><p> <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-BFC23CC1-102F-5740-A608-CF91C2BC3897">Create()</xref> </p> </li>

<li id="GUID-C1235A87-68BB-5AF4-80F6-DFB7DBA8432C"><p> <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-726A2A5F-18D3-55BD-9B92-0676266794C6">MediaState()</xref>  </p> </li>

<li id="GUID-BBAEC56C-DBA7-586C-A9CC-1E4E70A81096"><p> <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-1ADD0F5A-B561-54AE-BB2F-81AC3E8D81A4">DoDoorOpen()</xref>  </p> </li>

<li id="GUID-22D6992C-868B-5E18-9AA0-624EA51DB529"><p> <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-58829228-43A9-546B-8CFD-31DF8FBB0078">DoDoorClosed()</xref>  </p> </li>

<li id="GUID-04B7E650-7DA8-5F61-9D8E-89FC2B93AE20"><p> <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-F91B9434-5B90-5221-B5E6-D57F50391D81">ForceMediaChange()</xref>  </p> </li>

</ul> <p id="GUID-BFC23CC1-102F-5740-A608-CF91C2BC3897"><b>Create()</b> </p> <p> <xref href="GUID-2F974AD8-551B-35F0-B72C-99122913714D.dita#GUID-2F974AD8-551B-35F0-B72C-99122913714D/GUID-F96EF34B-7B38-37DC-9B34-E0D4D1963622"><apiname>DMMCMediaChange::Create()</apiname></xref>  </p> <p>The

function is intended to perform hardware initialisation on the MultiMediaCard

media change hardware, for example, setting port direction registers, binding

to the door open interrupt etc. </p> <p>The function is called after creation

of the <xref href="GUID-2F974AD8-551B-35F0-B72C-99122913714D.dita"><apiname>DMMCMediaChange</apiname></xref> derived class instance, which is

done during kernel initialisation when the MultiMediaCard controller Variant

DLL extension is loaded. </p> <p>The function has a default implementation

that just returns <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>. </p> <p>Your implementation

should return <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref> if the hardware initialisation is

successful, otherwise it should return one of the system-wide error codes

to indicate initialisation failure. Note that returning a value other than <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref> will

cause the kernel to panic and to fail to boot. </p> <p id="GUID-726A2A5F-18D3-55BD-9B92-0676266794C6"><b> MediaState()</b> </p> <p> <xref href="GUID-2F974AD8-551B-35F0-B72C-99122913714D.dita#GUID-2F974AD8-551B-35F0-B72C-99122913714D/GUID-A951EF31-83F1-3E07-A5BD-5342B6125ACF"><apiname>DMMCMediaChange::MediaState()</apiname></xref>  </p> <p>The

function should return the current state of the media, i.e. whether the media

door is open or closed. To indicate the state, it should return one of the <xref href="GUID-49F96729-2DDB-37E0-AE39-9BEF2B7FF7F9.dita"><apiname>TMediaState</apiname></xref> enum

values. </p> <p id="GUID-1ADD0F5A-B561-54AE-BB2F-81AC3E8D81A4"><b>DoDoorOpen()</b> </p> <p> <xref href="GUID-2F974AD8-551B-35F0-B72C-99122913714D.dita#GUID-2F974AD8-551B-35F0-B72C-99122913714D/GUID-6F734353-3458-3A8B-93E7-317674A1CAA4"><apiname>DMMCMediaChange::DoDoorOpen()</apiname></xref>  </p> <p>This

function should handle a media door open event. What needs to be done depends

on how door open and door closed events are detected. </p> <p>The most common

pattern is where the platform hardware is capable of generating an interrupt

when a door open event occurs, but cannot generate an interrupt when a door

closed event occurs. In this situation, the hardware provides a readable door

status that can be checked for the door closed state on a periodic basis (i.e.

polling). </p> <p>Assuming this, <codeph>DoDoorOpen()</codeph> would need

to enable a tick timer to poll for the door closing. The timer callback function

would check the state of the door, and if this showed a closed door, the timer

would be disabled and the function <xref href="GUID-C122D579-BB08-3084-A30E-DC857D6E7282.dita#GUID-C122D579-BB08-3084-A30E-DC857D6E7282/GUID-4F53C9F7-89C5-3CB6-A3D5-7DF40DAFF37F"><apiname>DMediaChangeBase::DoorClosedService()</apiname></xref> called.

This results in a call to <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-58829228-43A9-546B-8CFD-31DF8FBB0078">DoDoorClosed()</xref>. </p> <p>Note that the door open interrupt is cleared before this function is

called. The interrupt results in a call to <xref href="GUID-C122D579-BB08-3084-A30E-DC857D6E7282.dita#GUID-C122D579-BB08-3084-A30E-DC857D6E7282/GUID-6197984B-3884-367B-AE91-8E7E25203C95"><apiname>DMediaChangeBase::DoorOpenService()</apiname></xref>,

which in turn results in a call to this function <codeph>DoDoorOpen()</codeph>. </p> <p>Your

implementation would necessarily be different if an open door event could

not be signalled by an interrupt and a tick timer were to be used to poll

for an open door status. </p> <p id="GUID-58829228-43A9-546B-8CFD-31DF8FBB0078"><b>DoDoorClosed()</b> </p> <p> <xref href="GUID-2F974AD8-551B-35F0-B72C-99122913714D.dita#GUID-2F974AD8-551B-35F0-B72C-99122913714D/GUID-F26714BC-6648-349D-812D-6FD911602754"><apiname>DMMCMediaChange::DoDoorClosed()</apiname></xref>  </p> <p>This

function should handle a media door closed event. What needs to be done depends

on how door open and door closed events are detected. </p> <p>The most common

pattern is where the platform hardware is capable of generating an interrupt

when a door open event occurs, but cannot generate an interrupt when a door

closed event occurs. In this situation, the hardware provides a readable door

status that can be checked for the door closed state on a periodic basis (i.e.

polling). </p> <p>Assuming this, <codeph>DoDoorClosed()</codeph> would be

called by the timer callback function established by <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-1ADD0F5A-B561-54AE-BB2F-81AC3E8D81A4">DoDoorOpen()</xref> when the door status indicates a closed door; the function

would need to re-enable the door open interrupt. </p> <p>Your implementation

would necessarily be different if a closed door event were to be signalled

by an interrupt. </p> <p id="GUID-F91B9434-5B90-5221-B5E6-D57F50391D81"><b> ForceMediaChange()</b> </p> <p> <xref href="GUID-2F974AD8-551B-35F0-B72C-99122913714D.dita#GUID-2F974AD8-551B-35F0-B72C-99122913714D/GUID-2DB81D37-C930-3B3C-A64E-B734039A2C95"><apiname>DMMCMediaChange::ForceMediaChange()</apiname></xref>  </p> <p>This function is called by the local media device driver to force a remount

of the media device. For example to reopen a media driver in secure mode. </p> <p>It

should result in the same sequence of operations as would occur if a door

open event had taken place; for example, disabling the door open interrupt

and calling <xref href="GUID-C122D579-BB08-3084-A30E-DC857D6E7282.dita#GUID-C122D579-BB08-3084-A30E-DC857D6E7282/GUID-6197984B-3884-367B-AE91-8E7E25203C95"><apiname>DMediaChangeBase::DoorOpenService()</apiname></xref>. </p> </section>

<section id="GUID-7E709B21-8D38-5041-846F-CB7983B66834"><title>TMMCardControllerInterface

derived class (The factory class)</title> <p>This is a class, also known as <xref href="GUID-BE6AFD38-5952-537F-848C-C76C8F5FA9BF.dita#GUID-BE6AFD38-5952-537F-848C-C76C8F5FA9BF/GUID-26CFDD03-A4C4-5C96-88D4-5E750FDF69A3">the

controller factory</xref> that is responsible for deciding which peripheral

bus sockets are sockets that have been designated as a MultiMediaCard sockets

on this platform. It is also responsible for creating the platform-specific

layer objects associated with those MultiMediaCard sockets, i.e. the DMMCSocket,

DMMCStack, DMMCMediaChange, and DMMCPsu objects. </p> <p>This class defines

a number of pure virtual functions that need to be implemented in your Variant

DLL to provide the functionality that is specific to your platform. </p> <p>An

instance of your <xref href="GUID-B1F2C60B-E098-395F-8ED0-FF33E3EC9E4A.dita"><apiname>TMMCardControllerInterface</apiname></xref> derived class

is created in the <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-732EDE1D-452A-5A48-B5DB-1196C5F8BEBD">Variant

DLL entry point code</xref>. </p> <ul>

<li id="GUID-61BF196A-EFD3-57E1-98C2-A5B6350AC82E"><p> <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-2477BA25-2ADD-55CB-93F2-84F114221EBA">IsMMCSocket()</xref> </p> </li>

<li id="GUID-0FED2860-6710-517D-BB60-7FCBD043CEFB"><p> <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-829E686F-58F9-56A9-9EC4-CD59B14E127B">NewSocket()</xref> </p> </li>

<li id="GUID-3213A9CF-3155-513D-9F29-AB573018F23B"><p> <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-E0F612EB-85BC-533D-A71C-3FC93D9CC708">NewStack()</xref>  </p> </li>

<li id="GUID-9C8219D2-67EF-55B0-B01E-ACB2B0AC63CB"><p> <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-33A9C3DE-80EF-5895-BC7D-EA2ED6EB083B">MediaChangeID()</xref>  </p> </li>

<li id="GUID-B8309E5D-7F8A-5B62-81B3-6679AFBC9319"><p> <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-6B1FE81F-1497-5447-9286-B0BE54AE6831">NewMediaChange()</xref> </p> </li>

<li id="GUID-62725219-BAD2-528E-BC6A-84ACBA0A5C87"><p> <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-E969F613-01A3-54A7-8CC6-67F4A8E9558F">VccID()</xref>  </p> </li>

<li id="GUID-67AE2495-BCF2-51B6-9F52-78FA36A65F2A"><p> <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-083F38DB-AC65-5257-B169-2099194D3082">NewVcc()</xref>  </p> </li>

<li id="GUID-428FA30E-1E9A-50EA-BE3F-02E9B279E868"><p> <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-81A8BF8E-FB8B-596D-8C9A-690CD6449C12">Init()</xref>  </p> </li>

</ul> <p id="GUID-2477BA25-2ADD-55CB-93F2-84F114221EBA"><b>IsMMCSocket()</b> </p> <p> <xref href="GUID-B1F2C60B-E098-395F-8ED0-FF33E3EC9E4A.dita#GUID-B1F2C60B-E098-395F-8ED0-FF33E3EC9E4A/GUID-5EC9F2EE-5D14-37F9-9EFE-95BD1062C681"><apiname>TMMCardControllerInterface::IsMMCSocket()</apiname></xref>  </p> <p>Implement this function to indicate whether the peripheral bus socket, as

identified by the specified peripheral bus socket number, is designated as

a MultiMediaCard socket on this platform. It should return <xref href="GUID-781E8158-805B-3784-8FED-D7A191822FC3.dita"><apiname>ETrue</apiname></xref> if

the socket has been so designated, and return <xref href="GUID-A759CA2D-8327-348F-9337-4886E619D920.dita"><apiname>EFalse</apiname></xref> if

not. </p> <p>The function is called from <xref href="GUID-B1F2C60B-E098-395F-8ED0-FF33E3EC9E4A.dita#GUID-B1F2C60B-E098-395F-8ED0-FF33E3EC9E4A/GUID-2C6EA849-1B62-3158-A328-DB2A7149346C"><apiname>TMMCardControllerInterface::Create()</apiname></xref>,

which passes a socket number that can fall into the range 0 to <xref href="GUID-2C5A5F8F-381C-3B99-AADE-44474E629CC4.dita"><apiname>KMaxPBusSockets</apiname></xref>. </p> <p>Internally,

Symbian OS reserves space for an array of pointers to <xref href="GUID-C988CAE6-9073-3851-A0B0-5479D1A34CFB.dita"><apiname>DPBusSocket</apiname></xref> objects,

and this function allows the platform specific layer to identify which slot

is to be used for the <xref href="GUID-45B97680-1756-3559-8A2D-2F2E851AD6A7.dita"><apiname>DMMCSocket</apiname></xref> object. </p> <codeblock id="GUID-F1E0478A-8CE8-5E2F-87F8-AAFCCCE8A042" xml:space="preserve">GLDEF_D DPBusSocket* TheSockets[KMaxPBusSockets];</codeblock> <p>(This

array is internal to Symbian OS.) </p> <p>If, on this platform, a socket has

been designated as a MultiMediaCard stack, then the function not only returns <xref href="GUID-781E8158-805B-3784-8FED-D7A191822FC3.dita"><apiname>ETrue</apiname></xref>,

but also provides the media information for that socket, by filling in the

members of the <xref href="GUID-FC0F974E-9ABB-348B-9AE9-778B3A1F413A.dita"><apiname>SMediaDeviceInfo</apiname></xref> object passed in. </p> <p id="GUID-829E686F-58F9-56A9-9EC4-CD59B14E127B"><b>NewSocket()</b> </p> <p> <xref href="GUID-B1F2C60B-E098-395F-8ED0-FF33E3EC9E4A.dita#GUID-B1F2C60B-E098-395F-8ED0-FF33E3EC9E4A/GUID-90615A9A-BFC2-3E1B-B2AC-7D1CF322FC65"><apiname>TMMCardControllerInterface::NewSocket()</apiname></xref>  </p> <p>Implement

this function to create, and return a pointer to, an instance of the <xref href="GUID-45B97680-1756-3559-8A2D-2F2E851AD6A7.dita"><apiname>DMMCSocket</apiname></xref> class.

This can be a class derived from <codeph>DMMCSocket</codeph>, but this should

rarely be necessary. </p> <p>The function is called from <xref href="GUID-B1F2C60B-E098-395F-8ED0-FF33E3EC9E4A.dita#GUID-B1F2C60B-E098-395F-8ED0-FF33E3EC9E4A/GUID-2C6EA849-1B62-3158-A328-DB2A7149346C"><apiname>TMMCardControllerInterface::Create()</apiname></xref>. </p> <p>If

you create a <xref href="GUID-45B97680-1756-3559-8A2D-2F2E851AD6A7.dita"><apiname>DMMCSocket</apiname></xref> object, simply forward the peripheral

bus socket number and pointer to the password store; there is no need to do

anything with them. </p> <p>If you create an instance of a <xref href="GUID-45B97680-1756-3559-8A2D-2F2E851AD6A7.dita"><apiname>DMMCSocket</apiname></xref> derived

class, then just pass the socket number and pointer to the <codeph>DMMCSocket</codeph> constructor

in your constructor's ctor list. </p> <p>Note: </p> <ul>

<li id="GUID-FA8D57D9-0827-5090-A12B-A47C936B6F70"><p>The socket number can

fall into the range 0 to <xref href="GUID-2C5A5F8F-381C-3B99-AADE-44474E629CC4.dita"><apiname>KMaxPBusSockets</apiname></xref>, and is a value

for which <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-2477BA25-2ADD-55CB-93F2-84F114221EBA">IsMMCSocket()</xref> returned <xref href="GUID-781E8158-805B-3784-8FED-D7A191822FC3.dita"><apiname>ETrue</apiname></xref>. </p> </li>

<li id="GUID-3C4FCA1F-558D-5964-91F5-98588694DA70"><p>This function is only

called for sockets that are associated with MultiMediaCard devices as reported

by the function <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-2477BA25-2ADD-55CB-93F2-84F114221EBA">IsMMCSocket()</xref>. </p> </li>

</ul> <p id="GUID-E0F612EB-85BC-533D-A71C-3FC93D9CC708"><b>NewStack()</b> </p> <p> <xref href="GUID-B1F2C60B-E098-395F-8ED0-FF33E3EC9E4A.dita#GUID-B1F2C60B-E098-395F-8ED0-FF33E3EC9E4A/GUID-E2F99378-DD63-3BE0-8550-66EBF2C5D087"><apiname>TMMCardControllerInterface::NewStack()</apiname></xref>  </p> <p>Implement

this function to create, and return a pointer to, an instance of a <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-4C6CA873-A798-5C79-8838-0CC3C9E914FB">DMMCStack derived class</xref>. </p> <p>The function is called from <xref href="GUID-B1F2C60B-E098-395F-8ED0-FF33E3EC9E4A.dita#GUID-B1F2C60B-E098-395F-8ED0-FF33E3EC9E4A/GUID-2C6EA849-1B62-3158-A328-DB2A7149346C"><apiname>TMMCardControllerInterface::Create()</apiname></xref>. </p> <p>The

peripheral bus socket number and pointer to the socket object should be forwarded

to the <xref href="GUID-B5193656-9819-3E00-A335-EEF1726115A5.dita"><apiname>DMMCStack</apiname></xref> constructor in your class constructor's

ctor list. </p> <p>Note: </p> <ul>

<li id="GUID-CE363D03-6FEA-5AFE-A085-98D0FBAA9D52"><p>The socket number can

fall into the range 0 to <xref href="GUID-2C5A5F8F-381C-3B99-AADE-44474E629CC4.dita"><apiname>KMaxPBusSockets</apiname></xref>, and is a value

for which <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-2477BA25-2ADD-55CB-93F2-84F114221EBA">IsMMCSocket()</xref> returned <xref href="GUID-781E8158-805B-3784-8FED-D7A191822FC3.dita"><apiname>ETrue</apiname></xref>. </p> </li>

<li id="GUID-7F8F2267-E8C3-5AC5-92AB-7D3179BA6D10"><p>The socket is the object

created by <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-829E686F-58F9-56A9-9EC4-CD59B14E127B">NewSocket()</xref>. </p> </li>

<li id="GUID-DF7C2369-D225-54E4-B6F1-D444343E7084"><p>This function is only

called for sockets that are associated with MultiMediaCard devices as reported

by the function <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-2477BA25-2ADD-55CB-93F2-84F114221EBA">IsMMCSocket()</xref>. </p> </li>

</ul> <p id="GUID-33A9C3DE-80EF-5895-BC7D-EA2ED6EB083B"><b>MediaChangeID()</b> </p> <p> <xref href="GUID-B1F2C60B-E098-395F-8ED0-FF33E3EC9E4A.dita#GUID-B1F2C60B-E098-395F-8ED0-FF33E3EC9E4A/GUID-10B49F15-8ED5-3CA9-873A-788B87078367"><apiname>TMMCardControllerInterface::MediaChangeID()</apiname></xref>  </p> <p>Implement this function to report which media change object is to be

associated with the specified peripheral bus socket number. </p> <p>The function

is called from <xref href="GUID-B1F2C60B-E098-395F-8ED0-FF33E3EC9E4A.dita#GUID-B1F2C60B-E098-395F-8ED0-FF33E3EC9E4A/GUID-2C6EA849-1B62-3158-A328-DB2A7149346C"><apiname>TMMCardControllerInterface::Create()</apiname></xref>. </p> <p>The

media change object is represented by a number, which is simply an index value

that ranges from 0 to <xref href="GUID-92555AA1-73A5-3F88-8227-8D20C977F046.dita"><apiname>KMaxMediaChanges</apiname></xref>. Internally, Symbian

OS reserves space for an array of pointers to <xref href="GUID-C122D579-BB08-3084-A30E-DC857D6E7282.dita"><apiname>DMediaChangeBase</apiname></xref> objects,

and this function allows the platform specific layer to identify which slot

is to be used for the <xref href="GUID-2F974AD8-551B-35F0-B72C-99122913714D.dita"><apiname>DMMCMediaChange</apiname></xref> object that will

correspond to the specified socket number. </p> <codeblock id="GUID-08AE1956-86E0-544A-A95C-0D16DE6694D3" xml:space="preserve">GLDEF_D DMediaChangeBase* TheMediaChanges[KMaxMediaChanges];</codeblock> <p>(This array is internal to Symbian OS.) </p> <p>Note: </p> <ul>

<li id="GUID-1A4ED330-90E5-5215-8149-093987DD5D9B"><p>The socket number can

fall into the range 0 to <xref href="GUID-2C5A5F8F-381C-3B99-AADE-44474E629CC4.dita"><apiname>KMaxPBusSockets</apiname></xref>, and is a value

for which <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-2477BA25-2ADD-55CB-93F2-84F114221EBA">IsMMCSocket()</xref> returned <xref href="GUID-781E8158-805B-3784-8FED-D7A191822FC3.dita"><apiname>ETrue</apiname></xref>. </p> </li>

<li id="GUID-5EA3662D-82B2-529B-8DF4-2EAA9429990A"><p>This function is only

called for sockets that are associated with MultiMediaCard devices as reported

by the function <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-2477BA25-2ADD-55CB-93F2-84F114221EBA">IsMMCSocket()</xref>. </p> </li>

</ul> <p id="GUID-6B1FE81F-1497-5447-9286-B0BE54AE6831"><b>NewMediaChange()</b> </p> <p> <xref href="GUID-B1F2C60B-E098-395F-8ED0-FF33E3EC9E4A.dita#GUID-B1F2C60B-E098-395F-8ED0-FF33E3EC9E4A/GUID-2961273F-0D5A-3B9E-94D8-1FE216A57985"><apiname>TMMCardControllerInterface::NewMediaChange()</apiname></xref>  </p> <p>Implement this function to create, and return a pointer to, an instance

of a <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-C80E57B1-933B-55D7-949B-E68DB9B96B94">DMMCMediaChange

derived class</xref>. </p> <p>The function is called from <xref href="GUID-B1F2C60B-E098-395F-8ED0-FF33E3EC9E4A.dita#GUID-B1F2C60B-E098-395F-8ED0-FF33E3EC9E4A/GUID-2C6EA849-1B62-3158-A328-DB2A7149346C"><apiname>TMMCardControllerInterface::Create()</apiname></xref>. </p> <p>The

media change number should be forwarded to the <xref href="GUID-2F974AD8-551B-35F0-B72C-99122913714D.dita"><apiname>DMMCMediaChange</apiname></xref> constructor

in your class constructor's ctor list. </p> <p>Note: </p> <ul>

<li id="GUID-69B6384E-1B3C-567B-89AD-E0BE42E1F043"><p>The media change number

can fall into the range 0 to <xref href="GUID-92555AA1-73A5-3F88-8227-8D20C977F046.dita"><apiname>KMaxMediaChanges</apiname></xref>, and is the

value returned by <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-33A9C3DE-80EF-5895-BC7D-EA2ED6EB083B">MediaChangeID()</xref>. </p> </li>

<li id="GUID-FD2DA86D-5D0E-5661-AC09-55F10087D7A2"><p>This function is only

called for sockets that are associated with MultiMediaCard devices as reported

by the function <xref href="GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B.dita#GUID-E55B4FE5-517C-5A23-8ACA-E28EE202330B/GUID-2477BA25-2ADD-55CB-93F2-84F114221EBA">IsMMCSocket()</xref>. </p> </li>

</ul> <p id="GUID-E969F613-01A3-54A7-8CC6-67F4A8E9558F"><b>VccID()</b> </p> <p> <xref href="GUID-B1F2C60B-E098-395F-8ED0-FF33E3EC9E4A.dita#GUID-B1F2C60B-E098-395F-8ED0-FF33E3EC9E4A/GUID-1553B339-4171-396B-89E6-6C47C539D21F"><apiname>TMMCardControllerInterface::VccID()</apiname></xref>  </p> <p>Implement