u-blox ANTARIS 4 - Page 66

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Full Power State (On State)
InFullPowerStateallcomponentsoftheANTARIS
®
4chipsetarepoweredthroughpinVCC.Thisisthestandard
operationmode.DependingonCPUload,activityoftheperipheralhardwareandexternalloadontheI/Os,the
actualsupplycurrentrequirementmayvarysignificantly.
Sleep State (Off State)
Within this mode the CPU is powered and the receiver can be woken up
 with a request on the serial
communicationinterfaceoranexternalinterrupt.
If no computations need to be done, further power saving can be achieved by shutting down the clock.
Nevertheless,thesystemcanstillrespondtointerruptsourcesandwakeupagain.
If voltage supply is always present at
pin VCC, no backup battery is needed. The sleep  state is useful if the
systemisidleandwaitingforuserinputorsimilarevents.Therealtimeclock–asitremainsactiveandrunning–
canalsoschedulethesleepstatetowakeupthereceiveraftera
pre-definedperiodoftime.
 Note When operating an Antaris
®
4 receiver over the USB Port use the Backup State rather than Sleep
State.
Backup State (Off State)
BatteryBackupStateisaselectablepowersavestateinFXNmode.ContrarytoSleepState,onlytheRTCandthe
batterybackedupSRAMarepowered.Thisresultsinevenfurtherreducedpowerconsumption.The
receiver is
woken-upand goesthrough areset cycle when thepreprogrammed off timeexpiresor uponhardware reset.
Thismeans,configurationchangesnot savedtobatterybackupRAM(BBR)orFlashwillbelostafterwakingup
fromtheBackupState(seealsosection4.8).
CPU Only State (Off State)
In a custom application
 where the ARM7 processor of the GPS receiver is needed but no GPS functionality is
required, the entire GPS part of the system can be shut down while e.g. no position output and no satellite
trackingis required andthe CPU is executingthecustom code.This way thecustomer
has accessto 100%of
theCPUpower.(TheCPUclockisstillsuppliedfromtheRFsectiontothebasebandprocessor.)
TheRTCisstillpoweredtoallowfaststartupwhenGPSpositioningisrequired.
 Note TheNotavailablebydefault.
4.2.7.2 Position upon Request
Thereceivercanbeconfiguredtocalculatea
PVTsolutionuponrequestduringtheofftimeby:
• TheUBX-RXM(ReceiverManager)–POSREQ(PositionRequest)Message
• EXTINT0Pin
To configure theFixNOW™Mode (FXN) use theUBX–CFG–FXNmessage.Usethe UBX–CFG–RXM messageto
enableordisableFixNOW™Mode.
Theoptimalsettingsofthereceiverdependon
therequirementsoftheapplicationsuch asrequiredupdaterate
ormaximumresponsetime.
4.2.7.3 Waking up ANTARIS
®
4 GPS Receiver with external signals
If the ANTARIS
®
4 GPS Receiver has entered Sleep State and the power supply at pin VCC is present, various
triggerscanwakeupthereceiver:
GPSModules-SystemIntegrationManual(SIM)(incl.ReferenceDesign) ReceiverDescription
GPS.G4-MS4-05007-A1
  Page 66