TWRK60D100MUMTWR‐K60N512TowerModuleUser'sManualPage8of18
• GPIOwithpininterruptsupport,DMArequestcapability,digitalglitchfiltering
• Capacitivetouchsensinginputs(TSI)
• Debuginterfaces:JTAG,cJTAG,SWD
• Trace:TPIU,FPB,DWT,ITM,ETM,ETB
2.2 Clocking
TheKinetisMCUsstartupfromaninternaldigitallycontrolledoscillator(DCO).Softwarecanenable
oneortwoexternaloscillatorsifdesired.TheexternaloscillatorfortheMultipurposeClockGenerator
(MCG)modulecanrangefrom32.768KHzuptoa32MHzcrystalorceramicresonator.Theexternal
oscillatorfortheRealTimeClock(RTC)moduleacceptsa32.768kHzcrystal.
TheEXTALpinofthemainexternaloscillatorcanalsobedrivendirectlyfromanexternalclocksource.
TheTWR‐K60D100Mfeaturesa50MHzon‐boardclockoscillatorasseeninsheet4oftheschematics.
However,whentheK60EthernetMACisoperatinginRMIImode,synchronizationoftheMCUinput
clockandthe50MHzRMIItransferclockisimportant.Inthismode,theMCUinputclockmustbekept
inphasewiththe50MHzclocksuppliedtotheexternalPHY.Therefore,theTWR‐K60D100Mprovides
theoption(seedescriptionforJ6inTable5)toselecttheclockinputtotheMCUfrom1)theon‐board
50MHzsourceor2)anexternalclockfromtheCLKIN0pinonthePrimaryConnector3)routeCLKIN0
fromTWR‐SER50MHztoENET_1588_CLKIN.WhentheK60isoperatinginEthernetRMIImode,the
TowerperipheralmoduleimplementingtheRMIIPHYdeviceshoulddrivea50MHzclockonthe
CLKIN0signalthatiskeptinphasewiththeclocksuppliedtotheRMIIPHY.Refertosection2.10
“Ethernet”formoreinformation.
2.3 SystemPower
Instand‐aloneoperation,themainpowersourcefortheTWR‐K60D100Mmoduleisderivedfromthe
5.0VinputfromeithertheUSBmini‐Bconnector,J17,orthedebugheader,J16,whenashuntisplaced
onjumperJ15.Low‐dropoutregulatorsprovideeithera3.3Vor1.8Vsupplyfromthe5.0Vinput
voltageviaJ13.Refertosheet5oftheTWR‐K60D100Mschematicsformoredetails.
WheninstalledintoaTowerSystem,theTWR‐K60D100Mcanbepoweredfromeitheranon‐board
sourceorfromanothersourceintheassembledTowerSystem.Ifboththeon‐boardandoff‐board
sourcesareavailable,theTWR‐K60D100Mwilldefaulttotheoff‐boardsource.
TheV_BRDpowersuppliedtotheMCUisroutedthroughajumper,J14.Thejumpershuntcanbe
removedtoallowforeither1)alternateMCUsupplyvoltagestobeinjectedor2)themeasurementof
powerconsumedbytheMCU.
2.3.1 RTCVBAT
TheRealTimeClock(RTC)moduleontheK60hastwomodesofoperation,systempower‐upand
systempower‐down.Duringsystempower‐down,theRTCispoweredfromthebackuppowersupply,
VBAT.TheTWR‐K60D100Mprovidesabatteryholderforacoincellbatterythatcanbeusedasthe
VBATsupply.Theholdercanacceptcommon20mmdiameter3Vlithiumcoincellbatteries(e.g.2032,
2025).RefertothedescriptionofJ12inTable5“TWR‐K60D100MJumperTable”formoreinformation.