| Document | 
                            - General
                                    improvement of the documentation and its structure
 - Updated
                                    terminology used throughout the data sheet:
- Master is replaced by host
 - Slave is replaced by client
 
   
                         | 
| Device  | 
                            - Memories
- Improved
                                            BODCFG fuse description
 
  - Peripherals and
                                        Architecture
- Updated
                                            the Interrupt Vector Mapping table
 - Updated
                                            the REVID.MAJOR bit field description from 0x00 = A,
                                                0x01 = B to 0x01 = A, 0x02 = B
 
  - Ordering
                                        Information
- Added
                                            note for automotive-grade ordering codes (VAO
                                            suffix)
 
  - Package
                                        Drawings
- Added
                                            note in the Online Package Drawings section
 - Added the
                                                Package Marking section
 - Updated
                                            64-Pin VQFN style from MR to R4X
 - Added 32,
                                            48 and 64-Pin VQFN Wettable Flanks packages
 
   
                         | 
| Hardware Guidelines | 
                            - Digital Power
                                        Supply
- Updated
                                            primary decoupling capacitor value to 100 nF
 - Added
                                            optional decoupling capacitor (C3)
 - Added
                                            note
 
   
                         | 
| CPU | 
                            - Updated the
                                        AVR® CPU Architecture figure
 - Improved
                                    description for the RAMPZ register
  
                         | 
| NVMCTRL | 
                            - Updated the
                                        NVMCTRL Block Diagram figure
 - Removed offset
                                    column from the Available Interrupt Vectors and Sources
                                    table
  
                         | 
| CLKCTRL | 
                            - Updated the
                                        Phase-Locked Loop (PLL) section. Added initialization
                                    example.
 - The
                                        Auto-Tune section renamed to Manual Tuning and
                                        Auto-Tune. Added the new Manual Tuning
                                    section.
 - CLKCTRL.PLLCTRLA
                                    added to the list of registers requiring Configuration Change
                                    Protection (in the Registers Under Configuration Change
                                        Protection table)
 - Improved
                                    description of the RUNSTBY bit in the OSCHFCTRLA, OSCHFTUNE,
                                    PLLCTRLA, OSC32KCTRLA and XOSC32KCTRLA registers
 - Improved
                                    description of the XOSC32KCTRLA bit fields
 - Updated the name
                                    of the MULFAC bit field in the PLLCTRLA register from Frequency
                                    Select to Multiplication Factor
 - Improved
                                    description of the PLLCTRLA.MULFAC bit field 
  
                         | 
| SLPCTRL | 
                            - Improved the
                                        Sleep modes section
 - Updated the
                                        Sleep Mode Activity Overview tables
 - Added the
                                        Configuration Change Protection section
 - Updated
                                    description for the VREGCTRL.HTLLEN bit field
  
                         | 
| RSTCTRL | 
                            - Figures
                                        updated:
- Block
                                                Diagram
 - MCU
                                                Start-up, RESET Tied to
                                                  VDD
 - Brown-out Detector Reset
 - External Reset Characteristics
 
  - Figures added:
- Watchdog Reset
 - Software Reset
 
  - Updated the
                                        Logic Domains Affected by Various Resets table
 - Updated the
                                        Reset Time section
  
                         | 
| CPUINT | 
                            - Updated the
                                        CPUINT - Registers under Configuration Change
                                        Protection table
 - Improved the
                                        Non-Maskable Interrupts section
  
                         | 
| PORT | 
                            - System Clock
                                    renamed to Peripheral clock
 - Added
                                    initialization code example in the Multi-Pin
                                        Configuration section
 - Added
                                    clarification notes in following sections:
- Multi-Pin Configuration
 - Virtual Ports
 - PINCONFIG.ISC bit field description
 
   
                         | 
| BOD | 
                            - The VLMCTRL
                                    register renamed to VLMCTRLA
  
                         | 
| TCA | 
                            - Improved the
                                        Frequency (FRQ) Waveform Generation section:
- Added
                                            description on WOn offset
 - Added the
                                                Offset When Counting Up and Inverting
                                                Waveform Output figures
 - Added the
                                                Offset Equation Overview table
 - Added the
                                                Single-Slope Pulse-Width Modulation in Split
                                                Mode figure
 
  - Figures
                                        updated:
- Timer/Counter Block Diagram
 - Single-Slope Pulse-Width Modulation
 - Dual-Slope Pulse-Width Modulation
 
  - Added
                                    clarification notes in the following sections:
- Single-Slope Pulse-Width Modulation
 - Dual-Slope Pulse-Width Modulation
 - Events
 
  - Improved the
                                        Split Mode - Two 8-Bit Timer/Counters section
 - Improved bit
                                    fields and register description:
- Added
                                            clarification note in the CTRLC register
                                            description
 - Improved
                                            description for the LUPD bit field in the CTRLECLR and
                                            CTRLESET registers
 - Improved
                                            description for UPDOWN value of the EVACTA/B bit field
                                            in the EVCTRL register 
 
   
                         | 
| TCB | 
                            - General
                                    improvement of the documentation
  
                         | 
| TCD | 
                            - Updated the
                                    FAULTCTRL register bit fields name:
- CMPxEN
                                            renamed to CMPEN
 - CMPx
                                            renamed to CMP
 
   
                         | 
| RTC | 
                            - Removed note from
                                    the RTC Functional Description - Configure RTC
                                    section
 - Removed note from
                                    the PIT Functional Description - Initialization
                                    section
  
                         | 
| USART | 
                            - Updated
                                        terminology:
- Master is replaced by host
 - Slave is replaced by client
 
   
                         | 
| SPI | 
                            - General
                                    improvement of the documentation
 - Updated
                                        terminology:
- Master is replaced by host
 - Slave is replaced by client
 
   
                         | 
| TWI | 
                            - Improved
                                    description for the Client Initialization section
 - Improved
                                    description for register bit fields:
- The
                                            SDASETUP bit field from the CTRLA register
 - The
                                            INPUTLVL, FMPEN and SDAHOLD bit fields from the DUALCTRL
                                            register 
 - The FLUSH
                                            bit field from the MCTRLB register
 - The
                                            BUSSTATE bit field from the MSTATUS register
 - The SCMD
                                            bit field from the SCTRLB register
 
   
                         | 
| CCL | 
                            - Updated the
                                        Truth Table Output Value Selection figure
 - Updated the
                                        Linked LUT Input Selection figure
 - Improved
                                    description for the TRUTHn registers
 - Updated
                                        terminology:
- Master is replaced by host
 - Slave is replaced by client
 
   
                         | 
| ADC | 
                            - Added information
                                    on warm-up time in the Sleep Mode Operation section
 - Updated the
                                        Temperature Measurement section to include INITDLY
                                    and SAMPLEN configuration in the initialization steps 
  
                         | 
| DAC | 
                            - Removed
                                    conversion rate from the Feature section
 - Updated the
                                        DAC Block Diagram figure
 - Added the
                                        Signal Description section
 - Restructured the
                                        Operation section
- Added the
                                                DAC Output section
 - The
                                                DAC as Source For Internal Peripheral section
                                            renamed as Unbuffered Output as Source For Internal
                                                Peripherals
 - The
                                                DAC Output on Pin section renamed as
                                                Buffered Output
 
   
                         | 
| UPDI | 
                            - Renamed
                                    UPDICLKDIV to UPDICLKSEL
 - Updated the
                                        UPDI Clock Domains figure
 - Improved the
                                        Clocks section
 - Improved figures
                                    in the UPDI Instruction Set section
 - Updated Reset
                                    value for the STATUSA.UPDIREV bit field
 - Renamed the
                                    ASI_KEY_STATUS.CHIPERASE bit field to ASI_KEY_STATUS.CHER
 - Renamed the
                                    ASI_CTRLA.UPDICLKDIV bit field to ASI_CTRLA.UPDICLKSEL
 - Renamed the
                                    ASI_SYS_STATUS.UPDICLKDIV bit field to
                                    ASI_SYS_STATUS.UPDICLKSEL
  
                         | 
| Electrical characteristics | 
                            - Updated the
                                        Electrical Characteristics section
 - Added the
                                        Characteristics Graphs section
  
                         |