User's Manual

M2SD50NBT
Datasheet
 6
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Otherfunctionalityincludesthefollowing:
Feature Description
SystemClocking
(RTCBlock)
AnRTCblockcontrolstheclocksand powergoingtootherinternalmodules.Itsinputs
containsleeprequestsfromthesemodulesanditsoutputscontainclockenableand
powersignalswhichareusedtogatetheclocksgoingtothesemodules.TheRTCblock
alsomanagesresetsgoingtoothermoduleswiththedevice.TheM2SD50NBT’sclockingis
groupedintotwotypes:high‐speedandlow‐speed.
3.1.1.1 HighSpeedClocking
Thereference26MHzclocksourcedrivesthePLLandRFsynthesizerofWi‐Fiand
Bluetooth.Tominimizepowerconsumption,thereferenceclocksourceispoweredoffin
SLEEP,HOST_OFF,andOFFstates.
3.1.1.2 LowSpeedClocking
Thismodulerequiresanexternalsleepclock(32.768KHz)sourcefromhostplatform
throughpin‐50ontheNFGGgoldenfinger.ItisusedtoplaceBTintodeepsleepmode.For
Wi‐Fionlyapplication,itisnotneeded.
3.1.1.3 InterfaceClock
ThehostinterfaceclockrepresentsanotherclockdomainfortheM2SD50NBT.Thisclock
comesfromtheSDIOandisindependentfromtheotherinternalclocks.Itdrivesthehost
interfacelogicaswellascertainregisterswhichcanbeaccessedbythehostinHOST_OFF
andSLEEPstates.
MAC/BB/RFBlock
TheM2SD50NBTWirelessMACconsistsoffivemajorblocks:
 Hostinterfaceunit(HIU)forbridgingtotheAHBforbulkdataaccessesandAPBfor
registeraccesses
 Tenqueuecontrolunits(QCU)fortransferringTXdata
 TenDCFcontrolunits(DCU)formanagingchannelaccess

Protocolcontrolunit(PCU)forinterfacingtobaseband
 DMAreceiveunit(DRU)fortransferringRXdata
BasebandBlock
TheM2SD50NBTbasebandblock(BB)isthephysicallayercontrollerforthe802.11b/g/n
airinterface.
 Itmodulatesdatapacketsinthetransmitdirection
 Detectsanddemodulatesdatapacketsinthereceivedirection.
 Ithasadirectcontrolinterfacetotheradiotoenablehardwaretoadjustanaloggains
andmodesdynamically.
ClockSharing
 ClocksharingisimplementedontheM2SD50NBT.TheBluetoothchip(CSR8811)
receivesareferenceclockfromtheWi‐Fichip(QCA6004).WhenWi‐Fiisinpower
off/resetstate,Bluetoothisalsooff.
 External32.768KHzsignalpresentonpin50allowstheBTchiptogo
intodeepsleep
modeandconsumelowestamountofpower
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