File content as of revision 150:02e0a0aed4ec:

================ Revision history ============================================
5.0.0:
 - em_core: New module, contains API for enabling/disabling interrupts
   and implementing critical regions.
   em_core replaces em_int which is deprecated and marked for removal in a
   later release.
 - em_emu: Added EMU_SetBiasMode() for Series 1 Configuration 1 devices.
 - em_chip: Adding EMU_E210 errata fix in CHIP_Init().
 - em_adc: Changed default value of negSel in ADC_INITSINGLE_DEFAULT
   from adcNegSelAPORT0XCH1 to adcNegSelVSS.
 - em_emu, em_cmu, em_chip, em_system: Added support for Series 1,
   Configuration 2 parts (eg. EFR32MG12)
 - em_gpio: Fixed GPIO_ExtIntConfig() to enable correct interrupt number on
   Series 1 devices.
 - em_ldma: Updated LDMA_Init() and LDMA_StartTransfer() to support pointers
   to const memory.
 - em_ldma: Adding LDMA_DESCRIPTOR_SINGLE_P2P_BYTE which can be used when
   transfering bytes from one peripheral to another peripheral.
 - em_i2c: Fixed bug that may clear IEN bits set by the user.
 - em_emu: DCDC LN mode RCOBAND is now set based on LNFORCECCM.
 - em_emu: Member dcdcLnCompCtrl added to EMU_DCDCInit_TypeDef. This parameter
   allows configuraiton of 1uF or 4.7uF DCDC capacitor. 1uF is default for
   Series 1 Device Configuration 1 while 4.7 is default for Series 1
   Device Configuration 2 and later.
 - Updated documentation with more code examples for em_assert, em_common,
   em_cryotimer, em_gpcrc, em_ldma, em_msc, em_ramfunc, em_system, em_usart.

4.4.0:
 - em_emu: Putting DCDC in bypass mode before entering EM4S.
 - em_cmu: In the CMU_HFXOInit_TypeDef struct the following members have been
   deprecated and are no longer in use: autoStartEm01, autoSelEm01, and
   autoStartSelOnRacWakeup. Any application using the HFXO autostart feature
   must use the CMU_HFXOAutostartEnable() function instead.
 - em_emu: Updating DCDC LP comparator bias thresholds for EM2/3/4 according to
   updated reference manual. The thresholds are compared to the
   em234LoadCurrent_uA value of the EMU_DCDCInit_TypeDef struct.
 - em_msc: Fix for errata FLASH_E201 - Potential program failure after power on
   After a flash write the first word is checked to verify write operation. On
   a verification failure the first word is re-programmed.
 - em_adc: Enforcing at least 8 cycle aquisition time when reading ADC internal
   temp sensor using a 1.25V reference on platform 2 generation 1 devices.
 - em_adc: Setting GPBIASACC when initializing measurement of the ADC internal
   temp sensor as documented in the reference manual.
 - em_emu: Fix for errata EMU_E208 - Occasional Full Reset After Exiting EM4H
 - em_cmu: Added the possibility to configure external clock as HFXO
   and LFXO source via the CMU_HFXOInit() and CMU_LFXOInit() functions.
 - em_emu: Added EMU_EnterEM4H and EMU_EnterEM4S functions.
 - Fixed shift bug in ADC_EM2ClockConfig_TypeDef.
 - Added bounds check on ADC prescaler.
 - Updated ADC_INITSCAN_DEFAULT to match ADC_ScanInputClear().

4.3.1:
 - EFR32 and EFM32PG/JG em_cmu: Added automatic switching to HFXO
   PEAKDETSHUNTOPTMODE=CMD  mode after the first enable. This means automatic
   peak detection and shunt current optimization runs at the first call to
   CMU_OscillatorEnable(cmuOsc_HFXO, true, true) or
   CMU_ClockSelectSet(cmuClock_HF, cmuSelect_HFXO) only.
   Optimization can be restarted by calling CMU_OscillatorTuningOptimize(). This is
   required if the temperature changes by more than 100degC.
 - Added CMU_HFXOAutostartEnable() function to support automatic HFXO start and
   select.
 - Updated default timeouts for CMU_HFXOInit() to optimize HFXO startup
   time. The startup time reduction depends on the oscillator specification.
   The new defaults are safe for typical oscillator specifications.
 - em_ldma: LDMA_StartTransfer() now only enable a DMA channel once.
 - em_cmu: Fixed condtitional compilation bug in CMU_ClockSelectGet().
 - em_usart: Fixed bug in USART_BaudrateCalc() function.
 - em_usart: Improved corner cases in synchrounous baudrate calculation math.
 - em_emu.c: EMU_DCDCLnRcoBandSet() calls EMU_DCDCOptimizeSlice() as the slice
   configuration depends on RCO band.

4.3.0:
 - em_cmu: Removed unused fields from CMU_HFXOInit_TypeDef. The removed fields
   are regIshStartup and timeoutWarmSteady.
 - em_rtc.h: Added RTC_CounterSet function for modifying the RTC Counter.
 - em_burtc.c: Fixed bug when doing low frequency domain synchronization.
 - em_gpio.c: Deprecated GPIO_IntConfig(), use new function GPIO_ExtIntConfig()
   instead.
 - Removed deprecated file em_part.h.
 - em_dma.c: Replaced infinite loop on bus errors in default irq handler with
   an assert.
 - em_gpio.c: Use direct register write instead of BUS API in GPIO_PinModeSet
   to prevent glitches.
 - Fixed incorrect handling of CMU_CTRL_WSHFLE and CMU_HFPRESC_HFCLKLEPRESC in
   em_cmu.c for EFM32 Pearl and Jade Gecko.
 - Type enumerations cmuClock_HFLE and cmuSelect_HFCLKLE can now be used for
   all families to select or reference the divided down HF clock for LE peripherals.
 - Code size optimization in em_cmu.c.
 - Added GPCRC support.
 - Added support for WARNSEL, WINSEL and WDOGRSTDIS to em_wdog. Added interrupt
   functions. Added support for multiple WDOG instances. Deprecated functions
   WDOG_Enable(), WDOG_Feed(), WDOG_Init() and WDOG_Lock().
 - GPIO_EM4GetPinWakeupCause() now returns the content of the EM4WU field from
   the GPIO_IF register for platform 2 devices.
 - Added function GPIO_SlewrateSet() to set slewrate for GPIO ports.
 - Added fix for GPIO_E201 in CHIP_Init().
 - Added function CMU_HFRCOBandGet() and CMU_HFRCOBandSet() for platform 2.
   Functions with the same names are present for platform 1, but the parameter
   and return types are different. Platform 1 and 2 also do not support the same
   HFRCO/AUXHFRCO frequencies.
 - Added HFLE wait-state control to CMU_HFRCOBandSet(). This is a bug on
   EFM32 Wonder Gecko only as HFLE DIV4 is required at 24MHz, in between the 28HMz
   and 21MHz HFRCO bands.
 - Fixed reset-cause XMASKs for platform 2, gen 1 parts. Improved
   documentation in em_rmu.c.
 - Added support for configuring IrDA on USART1 for EFM32 Happy Gecko. The
   function USART_InitIrDA() is deprecated, and replaced by USARTn_InitIrDA().
 - Added module em_ramfunc. Fixed issue with calls from em_msc RAM code to Flash.
 - Updated current limiter threshold equations for LNCLIMILIMSEL, LPCLIMILIMSEL
   and DCDCZDETCTRL.
 - Member type EMU_DcdcLnTransientMode_TypeDef in EMU_DCDCInit_TypeDef changed to
   EMU_DcdcLnReverseCurrentControl_TypeDef to enable support for reverse current
   limiter.
 - EM2/3 current consumption optimization: Default value
   emuDcdcAnaPeripheralPower_AVDD in EMU_DCDCINIT_DEFAULT for EFR32
   changed to emuDcdcAnaPeripheralPower_DCDC.
 - EM2/3 current consumption optimization: DCDC_LP_NFET_CNT updated to 7

4.2.3:
 - Added DMA and LDMA functions to enable/disable channel requests.

4.2.2:
 - em_gpio.c: Use direct register write instead of BUS API in GPIO_PinModeSet
              to prevent glitches.

4.2.1:
 - Added errata fix for an issue that may cause BOD resets in EM2 when using
   DCDC-to-DVDD mode. The fix is implemented in EMU_DCDCInit().
 - Added function EMU_DCDCPowerOff() for boards with physically disconnected DCDC.
 - Current consumption is optimized for DCDC bypass mode. This update is
   implemented in EMU_DCDCInit().

4.2.0:
 - Updated I2C clock divider equation for platform 2 parts. Added constraints
   to HFPER clock frequency in I2C_BusFreqSet().
 - EMU EMU_EM23VregMode_TypeDef replaced with a bool.
 - Added support for GPIO alternate drive strength and alternate control modes.
 - DCDC setup is simplified. More tuning and optimization settings added to
   EMU_DCDCInit().
 - Added member pinRetentionMode to EMU_EM4Init_TypeDef.
 - Added function EMU_UnlatchPinRetention() to support unlatching of pin
   retention in EM4H/S.
 - Fixed bug in ADC_InitScan() which caused a overwrite of single conversion
   mode calibration values.
 - Added support for CRYPTO module on EFM32 Pearl and Jade Gecko (em_crypto.c/h).

4.1.1:
 - EMU_DCDCInit() updated with new parameters for EM2 and 3. Current consumption
   with DCDC at expected levels for EFR32 and EFM32 Pearl and Jade Gecko.
 - EMU_DCDCInit_TypeDef updated with more parameters. EMU_DcdcLpcmpBiasMode_TypeDef
   is removed.
 - More assertions added to EMU_DCDCInit().
 - HFXO default parameters updated.
 - ADC defaults updated.
 - RMU pin mode set fixed.
 - Added missing define for cmuSelect_ULFRCO.
 - Added missing functions for handling peripheral interrupts.
 - Added support for VMON.

4.1.0:
 - New signature for RMU_ResetControl() function.
 - The typedef EMU_EM23Init_TypeDef which is a parameter to EMU_EM23Init()
   has got a new definition.
 - Initial support _SILICON_LABS_32B_PLATFORM_2 devices added.

4.0.0:
 - Use ARM CMSIS version 4.2.0.
 - New style version macros in em_version.h.

3.20.14:
 - USB release only.

3.20.13:
 - Added new style family #defines in em_system.h, including EZR32 families.
 - Fixed I2C_FREQ_STANDARD_MAX macros.
 - Fixed bug in MSC_WriteWord which called internal functions that were linked
   to flash for armgcc. All subsequent calls of MSC_WriteWord should now be
   linked to RAM for all supported compilers. The internals of MSC_WriteWord()
   will check the global variable SystemCoreClock in order to make sure the
   frequency is high enough for flash operations. If the core clock frequency
   is changed, software is responsible for calling MSC_Init or
   SystemCoreClockGet in order to set the SystemCoreClock variable to the
   correct value.
 - Added errata fix IDAC_101.

3.20.12:
 - Added errata fix EMU_108.
 - #ifdef's now use register defines instead of a mix of register and family defines.
 - Added a case for when there are only 4 DMA channels available:
   Alignment was (correctly) defined at 7 bit, but got asserted for 8 bit, leading
   to unpredictable tripped asserts.
 - Added USART_INITPRSTRIGGER_DEFAULT defined structure to support HWCONF.
 - Added support for LFC clock tree.
 - Added CMU_USHFRCOBandSet() and CMU_USHFRCOBandGet().

3.20.10:
 - Maintenance release, no changes.

3.20.9:
 - Added support for Happy Gecko including support for the new oscillator USHFRCO.
 - Added MSC_WriteWordFast() function. This flash write function has a similar
   performance as the old  MSC_WriteWord(), but it disables interrupts and
   requires a core clock frequency of at least 14MHz. The new MSC_WriteWord()
   is slower, but it does not disable interrupts and may be called with core
   clock frequencies down to 1MHz.
 - Fixed a bug in EMU_EnterEM4() that set other EM4 configuration bits to 0
   on EM4 entry.
 - Added EMU_EM23Init().
 - Fixed a bug in CMU_FlashWaitStateControl() where it failed to set the
   required wait-state configuration if the MSC is locked.
 - Added EMU interrupt handling functions.
 - BURTC_Reset() changed to use async reset RMU_CTRL_BURSTEN instead of
   reset value writeback. This makes the function independent of a selected
   and enabled clock.
 - BURTC_Sync() now returns without waiting for BURTC->SYNCBUSY to clear
   when no clock is selected in BURTC_CTRL_CLKSEL.
 - Fixed assertion bug in ACMP_ChannelSet() that checked the negSel parameter
   against the wrong upper bound.

3.20.7:
 - Fixed CMU_MAX_FREQ_HFLE macro for Wonder family.
 - Fixed MSC_WriteWord() bug.
 - Added syncbusy wait in RTC_Reset() for Gecko family.

3.20.6:
 - Corrected fix for Errata EMU_E107.

3.20.5:
 - Updated license texts.
 - Removed unnecessary fix for Wonder Gecko.
 - Updated LFXO temperature compensation in CHIP_Init().
 - Changed LESENSE_ScanStart, LESENSE_ScanStop, LESENSE_DecoderStart,
   LESENSE_ResultBufferClear() and LESENSE_Reset() functions to wait until
   CMD register writes complete in order to make sure CMD register writes do
   not break each other, and for register values to be consistent when
   returning from functions that write to the CMD register.
 - Added fix for Errata EMU_E107.
 - Added family to SYSTEM_ChipRevision_TypeDef.
 - Fixed bug in function AES_OFB128 which failed on Zero Gecko.
 - Fixed RMU_ResetCauseGet() to return correct reset causes.
 - Fixed bug in RTC_CounterReset() which failed to reset counter immediately
   after return on Gecko devices.
 - Added static inline non-blocking USART receive functions (USART_Rx...).
 - Added function SYSTEM_GetFamily().
 - Added function DAC_ChannelOutputSet().
 - Fixed MSC_WriteWord() to not use WDOUBLE if LPWRITE is set.

3.20.2:
 - Fixed bug regarding when MEMINFO in DEVINFO was introduced.
   The correct crossover is production revision 18.
 - Fixed bug in WDOG_Feed() which does not feed the watchdog if the watchdog
   is disabled. Previously, the watchdog was broken after WDOG_Feed() fed it
   when it was disabled.
-  Fixed issue in em_i2c.c, which should set the NACK bit in the I2C CMD
   register for the next to last byte received. The exception is when only
   one byte is to be received. Then the NACK bit must be set like the
   previous code was doing.
-  Added function BURTC_ClockFreqGet() in order to determine clock frequency
   of BURTC.
-  Fixed bug in BURTC_Reset() which made a subsequent call to BURTC_Init hang.
-  Added support for the IDAC module on the Zero Gecko family, em_idac.c/h.
-  Fixed bug in DAC_PrescaleCalc() which could return higher values than
   the maximum prescaler value. The fix makes sure to return the max prescaler
   value resulting in possible higher DAC frequency than requested.
-  Fixed I2C_BusFreqSet to use documented values for Nlow and Nhigh values,
   and do not decrement the div(isor) by one according to the formula because
   this resulted in higher I2C bus frequencies than desired.

3.20.0:
 - LEUART: Added LEUART_TxDmaInEM2Enable() and LEUART_RxDmaInEM2Enable() for
   enabling and disabling DMA LEUART RX and Tx in EM2 support.

3.0.3:
 - Internal release for testing Wonder Gecko support.
 - SYSTEM: Added function to enable/disable FPU access on Wonder parts,
           SYSTEM_FpuAccessModeSet().
 - USART: Added USART_SpiTransfer() function.

3.0.2:
 - MSC: In MSC_WriteWord(), added support for double word write cycle support
   (WDOUBLE) on devices with more than 512KiBytes of Flash memory. This can
   almost double the speed of the MSC_WriteWord function for large data sizes.
 - MSC: In MSC_ErasePage(), added support for devices with Flash page size
   larger than 512 bytes, like Giant and Leopard Gecko.
 - CMU: Fixed bug in CMU_ClockDivSet(). Clear HFLE and HFCORECLKLEDIV flags when
   the core runs at frequencies up to 32MHz.
 - CMU: Fixed bug in CMU_ClockEnable(): Set the HFLE and HFCORECLKLEDIV flags
   when the CORE clock runs at frequencies higher than 32MHz.
 - CMU: Fixed bug in CMU_ClockSelectSet(): Set HFLE and DIV4 factor for peripheral
   clock if HFCORE clock for LE is enabled and the CORE clock runs at
   frequencies higher than 32MHz.
 - BITBAND: Added BITBAND_PeripheralRead() and BITBAND_SRAMRead() functions.
 - DMA: Added #ifndef EXCLUDE_DEFAULT_DMA_IRQ_HANDLER around DMA_IRQHandler in
   order for the user to implement a custom IRQ handler or run without a DMA
   IRQ handler by defining EXCLUDE_DEFAULT_DMA_IRQ_HANDLER with the -D compiler
   option.
 - BURTC: In functions BURTC_Init() and BURTC_CompareSet(), moved SYNCBUSY
   loops in front of modifications of registers COMP0 and LPMODE.
 - MSC: Fixed ram_code section error on Keil toolchain.
 - MSC: Removed uneeded code from MSC init and deinit which would have no
   effect (Big thanks to Martin Schreiber for reporting this bug!).
 - System: Added access functions for reading some values out of the Device
   Information page.

3.0.1:
 - LFXO fix for Giant family.
 - USART: Fix for EFM32TG108Fxx which does not have USART0.
 - EBI: The write to the CTRL register now happens before the ROUTE registers
   are set. This avoids potential glitches.
 - LESENSE: Fix issue when using lesenseAltExMapACMP.
 - TIMER: Fix compilation on devices where ADC is not available.
 - LCD: Fix bug where Aloc field would not be set to 0.
 - BURTC: Fix Reset function by adding reset of COMP0 register and removing
   reset of POWERDOWN register. The POWERDOWN register cannot be used to
   power up the blocks after it has been powered down.
 - CMU: Fixed bug where ClockDivSet, ClockDivGet and ClockFreqGet didn't work for
   cmuClock_LCDpre clock. Also corrected 3 wrongly typed constants.
 - CMU: Fixed bug where LFBE field in LFCLKSEL was not cleared before setting
   bit-value.
 - CMU: Fixed bug with CMU_ClockSelectGet. Did not give correct return value
   for cmuClock_LFB.
 - I2C: Fixed bug where I2C_Init would set divisor depending on the previous
   master/slave configuration, not the one set in the initialization.
 - I2C: Fixed issue in the function I2C_BusFreqSet (called by I2C_Init). The
   input parameter 'I2C_ClockHLR_TypeDef type' was not in use. The fix enables
   the parameter to add support for 'i2cClockHLRAsymetric' and 'i2cClockHLRFast'
   modes. In order to use 'i2cClockHLRAsymetric' and 'i2cClockHLRFast' the
   frequency of the HFPER clock may need to be increased.
 - OPAMP: Fixed bug in the function OPAMP_Enable where an incorrect register
   was used when setting the OPA2 calibration value.
 - LEUART: Fixed issue in LEUART_BaudrateSet when a high clock frequency and a
   low baudrate can overflow the clock divisor register (CLKDIV). The fix uses
   an assert statement to check whether the calculated clock divisor is out of
   range.
 - USART: Fixed issue in USART_BaudrateAsyncSet when a high clock frequency and
   a low baudrate can overflow the clock divisor register (CLKDIV). The fix uses
   an assert statement to check whether the calculated clock divisor is out of
   range.

3.0.0:
 - efm32lib renamed emlib, as it will include support for non-EFM32 devices
   in the future
 - Added CMSIS_V3 compatibility fixes, and use of CMSIS_V3 definitions
 - See Device/Changes-EnergyMicro.txt for detailed path changes
 - New prefixes of all files, efm32_<peripherqal>.c/h to em_<peripheral>.c/h
 - New names for readme and changes files
 - RMU - BUMODERST not masked away when EM4 bits has been set
 - CMU - CMU_LFClkGet now accounts for ULFRCO bit for Tiny Gecko

2.4.1:
 - New, open source friendly license
 - Fixed BURTC initialization hang if init->enable was false
 - Fixed CMU issue with USBC and USB checks not being used correctly
 - Added CMU feature, missing TIMER3 support
 - Improved accuracy of SPI mode for USART baudrate calculation
 - Corrected USBC HFCLKNODIV setting to comply with new header file defines

2.4.0:
 - Added efm32_version.h defining software version number
 - Added BURTC support for Giant and Leopard Gecko
 - Added RMU_ResetControl for BU reset flag
 - Added some missing features to EMU for back up domain and EM4 support
 - ADC TimebaseCalc(), Giant/Leopard Gecko have max 5 bits in TIMEBASE field
 - Removed EMU Backup Power Domain threshold setings from EMU_BUPDInit, added
   EMU_BUThresRangeSet() and EMU_BUThresholdSet() API calls. Threshold values
   are factory calibrated and should not usually be overridden by the user.

2.3.2:
 - Added Tiny Gecko and Giant Gecko support in RMU for new reset causes
 - CMU_ClockFreqGet will now report correct clock rates if HFLE is set (/4)
 - Added Giant Gecko specific MSC_MassErase(), erase entire flash
 - Added Giant Gecko specific MSC_BusStrategy (inline) function
 - MSC_Init() will now configure TIMEBASE correctly according to AUXHFRCO clock
   rate for Tiny Gecko and Giant Gecko

2.3.0:
 - USART - Added USART_InitPrsTrigger to initialize USART PRS triggered
   transmissions.
 - CMU - numerous updates, now supports full clock tree of Giant/Tiny Gecko
 - CMU_ClockDivSet/Get will now use real dividend and not logarithmic values
   as earlier. Prior enumerated values have been kept for backward compatibility.
 - Added support for CMU HFLE and DIV4 factor for core clock for LE
   peripherals
 - Added support for alternate LCD segment animation range for Giant Gecko
 - Fixed bug: Don't enable VCMP low power reference until after warm up,
   allow biasprog value of 0 in VCMP_Init()
 - Added support for ALTMAP (256MB address map) in EBI_BankAddress()
 - TIMER_Init() will now reset CNT value

2.2.2:
 - Added DAC0 channel 0 and 1 to ACMP for Tiny and Giant devices
 - Fixed bug in CMU for MSC WAITSTATE configuration, leading to too high wait
   states depending on clock rate
 - Fixed bug in CMU for UART1 clock enable

2.2.1:
 - UART_Reset() and LEUART_Reset() will now reset ROUTE register as well, this
   will mean GPIO pins will not be driven after this call. Take care to ensure
   that GPIO ROUTE register is configured after calls to *UART_Init*Sync
 - Fixed problems with EFM_ASSERT when using UART in USART API
 - Added Giant Gecko support for EBI (new modes and TFT direct drive)
 - Added Giant Gecko support for CMU 2 WAIT STATES, and I2C1
 - Added Giant Gecko support for UART1 in CMU
 - Added Giant Gecko support for DMA LOOP and 2D Copy operations

2.1.0:
 - EMU_Restore will now disable HFRCO if it was not enabled when entering
   an Energy Mode
 - Run time changes only applies to Gecko devices, filter out Tiny and Giant
   for CHIP_Init();
 - Added const specificers to various initialization structures, to ensure
   they can reside in flash instead of SRAM
 - Bugfix in efm32_i2c.c, keep returning i2cTransferInProgress until done

2.0.1:
 - Changed enum OPAMP_PosSel_TypeDef. Enum value opaPosSelOpaIn changed from
   DAC_OPA0MUX_POSSEL_OPA1IN to DAC_OPA0MUX_POSSEL_OPA0INP.
 - Bugfix in efm32_lesense.h, LESENSE_ChClk_TypeDef now contains unshifted
   values, fixed the implementation in efm32_lesense.c where the bug prevented
   the sampleClk to be set to AUXHFRCO.

2.0.0:
 - USART_Init-functions now calls USART_Reset() which will also disable/reset
   interrupt
 - USART_BaudrateSyncSet() now asserts on invalid oversample configuration
 - Added initialization of parity bit in LEUART_Init()
 - Added Tiny Gecko support for CMU, ULFRCO, LESENSE clocks and continuous
   calibration
 - Added Tiny Gecko support for GPIO, EM4 pin retention and wake up support
 - Added Tiny Gecko support for I2S, SPI auto TX mode on USART
 - Added Tiny Gecko support for CACHE mesasurements for MSC module
 - Added Tiny Gecko support for LCD module (with no HIGH segment registers)
 - Added Tiny Gecko support for TIMER, PWM 2x,  (DT lock not supported)
 - Added Tiny Gecko support for LESENSE module
 - Added Tiny Gecko support for PRS input in PCNT
 - Added Tiny Gecko support for async signals in PRS, PRS_SourceAsyncSignalSet()
 - Initial support for some Giant Gecko features, where overlapping with Tiny
 - Removed LPFEN / LPFREQ support from DAC
 - Fixed comments around interrupt functions, making it clear it is bitwise
   logical or interrupt flags
 - Fixed PCNT initialization for external clock configurations, making sure
   config is synchronized at startup to 3 clocks. Note fix only works for
   >revC EFM32G devices.
 - Fixed efm32_cmu.c, EFM_ASSERT statement for LEUART clock div logic was
   inverted
 - Fixed ADC_InitScan, PRSSEL shift value corrected
 - Fixed CMU_ClockFreqGet for devices that do not have I2C
 - Fixed I2C_TransferInit for devices with more than one I2C-bus (Giant Gecko)
 - Changed ACMP_Disable() implementation, now only disables the ACMP instance
   by clearing the EN bit in the CTRL register
 - Removed ACMP_DisableNoReset() function
 - Fixed ACMP_Init(), removed automatic enabling, added new structure member
   "enaReq" for ACMP_Init_TypeDef to control, fixed the EFM_ASSERT of the
   biasprog parameter
 - Added default configuration macro ACMP_INIT_DEFAULT for ACMP_Init_TypeDef
 - Fixed ACMP_CapsenseInit(), removed automatic enabling, added new structure member
   "enaReq" for ACMP_CapsenseInit_TypeDef to control, fixed the EFM_ASSERT of
   the biasprog parameter
 - Changed the name of the default configuration macro for
   ACMP_CapsenseInit_TypeDef to ACMP_CAPSENSE_INIT_DEFAULT
 - Added RTC_Reset and RTC_CounterReset functions for RTC

1.3.0:
 - MSC is automatically enabled/disabled when using the MSC API. This saves
   power, and reduces errors due to not calling MSC_Init().
 - Added API for controlling Cortex-M3 MPU (memory protection unit)
 - Adjusted bit fields to comply with latest CMSIS release, see EFM_CMSIS
   changes file for details
 - Fixed issue with bit mask clearing in ACMP
 - Functions ACMP_Enable and ACMP_DisableNoReset added
 - Added comment about rev.C chips in PCNT, CMD_LTOPBIM not neccessary any more
 - Added missing instance validity asserts to peripherals (ACMP, LEUART, USART)
 - Fixed UART0 check in CMU_ClockFreqGet()
 - Fixed command sync for PCNT before setting TOPB value during init
 - Fixed instance validity check macro in PCNT
 - Fixed TIMER_Reset() removed write to unimplemented timer channel registers
 - Fixed EFM_ASSERT statements in ACMP, VCMP
 - General code style update: added missing curly braces, default cases, etc.

1.2.1:
 - Feature complete efm32lib, now also includes peripheral API for modules
   AES,PCNT,MSC,ACMP,VCMP,LCD,EBI
 - Fixed _TIMER_CC_CTRL_ICEDGE flags for correct timer configuration
 - Fixed ADC calibration of Single and Scan mode of operation
 - Added PCNT (ChipRev A/B PCNT0 errata NOT supported) and AES support
 - Fixed conditional inclusion in efm32_emu.h
 - Fixed code for LEUART0 for devices with multiple LEUARTs.
 - Fixed incorrect setting of DOUT for GPIO configuration

1.1.4
 - Fix for TIMER_INIT_DEFAULT

1.1.3:
 - Added ADC, DAC, LETIMER, PRS, TIMER (except DTI) support
 - Added utility for fetching chip revision (efm32_system.c/h)
 - Removed RTC instance ref in API, only one RTC will be supported
   (Affects also define in efm32_cmu.h)
 - Added default init struct macros for LEUART, USART
 - Added msbf parameter in USART synchronous init struct, USART_InitSync_TypeDef.
 - Updated reset for I2C, USART, LEUART to also reset IEN register.
 - Corrected fault in GPIO_PortOutSet()

1.1.2:
 - Corrected minor issues in EMU, EM3 mode when restoring clocks
 - Corrected RMU reset cause checking
 - Changed GPIO enumerator symbols to start with gpio (from GPIO_)
 - Changed CMU and WDOG enum typedefs to start with CMU_/WDOG_ (from cmu/wdog)
 - Added USART/UART, LEUART, DMA, I2C support

1.1.1:
 - First version including support for CMU, DBG, EMU, GPIO, RTC, WDOG