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*** Changes in AVR-LibC-2.2.0:

* General:

  - Project moved to Github

  - Support for many new devices has been added, like devices from the
    AVR 0-series, 1-series, 2-series, AVR-Dx and AVR-Ex, but also for
    some older devices.

  - Parts of the user manual have been reworked, like the inline assembly
    Cookbook and the documentation of memory sections.

  - The multilib layout of the library, and what device belongs to which
    multilib variant, is no more hard coded in AVR-LibC but follows the
    compiler's multilib layout.

* Improvements and additions:

  - Add support to new multilib layout / 64-bit [long] double compiler
    (Issues #642, #670)

  - Added support for new devices (Issue #824):
    ATtiny202 ATtiny204 ATtiny212 ATtiny214 ATtiny402 ATtiny404
    ATtiny406 ATtiny412 ATtiny414 ATtiny416 ATtiny417 ATtiny424
    ATtiny426 ATtiny427 ATtiny804 ATtiny806 ATtiny807 ATtiny814
    ATtiny816 ATtiny817 ATtiny824 ATtiny826 ATtiny827 ATtiny1604
    ATtiny1606 ATtiny1607 ATtiny1614 ATtiny1616 ATtiny1617 ATtiny1624
    ATtiny1626 ATtiny1627 ATtiny3214 ATtiny3216 ATtiny3217 ATtiny3224
    ATtiny3226 ATtiny3227 ATmega808 ATmega809 ATmega1608 ATmega1609
    ATmega3208 ATmega3209 ATmega4808 ATmega4809

  - Added support for AVR-Dx devices (Issue #881):
    AVR16DD14 AVR16DD20 AVR16DD28 AVR16DD32 AVR32DA28 AVR32DA32
    AVR32DA48 AVR32DB28 AVR32DB32 AVR32DB48 AVR32DD14 AVR32DD20
    AVR32DD28 AVR32DD32 AVR64DA28 AVR64DA32 AVR64DA48 AVR64DA64
    AVR64DB28 AVR64DB32 AVR64DB48 AVR64DB64 AVR64DD14 AVR64DD20
    AVR64DD28 AVR64DD32 AVR128DA28 AVR128DA32 AVR128DA48 AVR128DA64
    AVR128DB28 AVR128DB32 AVR128DB48 AVR128DB64
    AVR64DU28 AVR64DU32

  - Added support for AVR-Ex devices:
    AVR16EA28 AVR16EA32 AVR16EA48 AVR16EB14 AVR16EB20 AVR16EB28 AVR16EB32
    AVR32EA28 AVR32EA32 AVR32EA48 AVR64EA28 AVR64EA32 AVR64EA48

  - Added support for Reduced Tiny devices:
    ATiny102 ATtiny104

  - Added support for Classic devices:
    ATmega168PB ATmega328PB ATmega324PB

  - Added a new module to lib<mcu>.a that can be used as part of the
    startup code by the compiler.  The compiler will link the code when
    a device from the AVR-Dx or AVR-Ex families uses a non-default layout
    of NVMCTRL_CTRLB.FLMAP (Issue #931, Binutils PR31124, GCC PR112944).
    For more details on the feature see the GCC v14 release notes at
    https://gcc.gnu.org/gcc-14/changes.html#avr

  - Added support for: strndup.

  - Added support for: PROGMEM_FAR, PSTR_FAR, strchr_PF.

  - Added support for ccp_write_spm() in avr/cpufunc.h

  - The delay routines no more include math.h but use built-in functions
    __builtin_fabs and __builtin_ceil instead of fabs and ceil.  This means
    the delay routines are now independent of -f[no-]freestanding (Issue 580).

  - Added macros pgm_read_qword, pgm_read_qword_near, pgm_read_qword_far.

  - Added inline functions to read from progmem that return a type as
    indicated by the function name, like char pgm_read_char (const char*).
    The functions adjust to -mint8, -mdouble= and -mlong-double=.
    Functions for fixed-width types are pgm_read_i64, pgm_read_u24, etc.
    * Functions that read from beyond 64 KiB are suffixed _far and take
      an uint_farptr_t as argument.
    * pgm_read_float has been turned from a macro that takes uint16_t to
      an inline function that takes const float*.
    * pgm_read_byte, pgm_read_word and pgm_read_dword remain as they were
      and still take an uint16_t argument for compatibility and legacy code.

  - Added experimental templates pgm_read<> and pgm_read_far<>.  They are
    only available when macro __pgm_read_template__ is defined.

  - Added EEPROM support for: double, long double, uint64_t (*_qword).

  - AVR-LibC does not use section .progmem.* any more for lookup tables and
    string literals.  Instead, .progmemx.* is used which does not require
    that the data resides in the lower 64 KiB of program memory.
    This means that on devices with more than 64 KiB of program memory,
    the ELPM instruction is used to read the data where formerly it was LPM.
    Hence code size and execution times on such devices will slightly
    increase for functions from the printf and scanf families, and for libm
    functions that use power series.  (Issue #962).
    Notice that only since Binutils v2.29 (PR21849), section .progmemx is
    located after the .text sections.

  - The startup code now defines symbols like __DATA_REGION_LENGTH__ and
    __DATA_REGION_ORIGIN__ according to the memories of the used AVR device
    (Issue #936).  These symbols are used by the default linker scripts to
    diagnose when the text or data region overflows.
    To date, only a core specific default value was used, but the devices
    that belong to the same core architecture have different memory sizes.

  - The pgm_read_* and pgm_read_*_far macros and functions now also work for
    the Reduced Tiny devices. (Issue #563).  The implementation assumes that
    GCC implements PR71948 which was added in v7.  Notice that on Reduced Tiny:
    * There is no need for PROGEM at all because all const objects in static
      storage are located in program memory since Binutils v2.27 (PR20849).
    * Even when PROGMEM is used, no pgm_read functions or macros are required.
      See the GCC documentation on the __progmem__ attribute for Reduced Tiny.

* Issues closed:

  - [patch #9543] Add avrxmega3 devices. #824

  - [bug #49567] Use meta-info from --print-multi-lib and
    --print-multi-directory #642

  - [bug #57071] Fix math.h and function names that block 64-bit
    double #670

  - Issue #476 [bug #32945] RAMPZ clobbered in far-pointer library.
    Functions from the far-pointer library in libc/pmstring like
    memcpy_PF that read from program memory using ELPM must set
    RAMPZ to the high byte of the 24-bit address.  On devices that
    don't use RAMPZ exclusively with ELPM, RAMPZ has to be reset when
    the function is finished.  These are devices with an EBI (External
    Bus Interface): ATxmega64A1, ATxmega64A1U, ATxmega128A1,
    ATxmega128A1U,  ATxmega128A4U.

  - Add device support to avr/power.h for:
    ATtiny441 ATtiny841

  - FDEV_SETUP_STREAM from stdio.h now works with C++ (Issue #898)

  - More than 80, mostly historic issues have been closed -- too many
    to mention all of them here

  - Fixed wrong prototypes of frexp, frexpf, frexpl in math.h (Issue #929)

  - time.h: function mktime() is off by 1h when [EU] DST is active (Issue #967)

* Pull requests:

  - Logo [#969]
  - Documentation fixes [#968]
  - Issue #962 - libm: Use ELPM for tables on ELPM devices. [#964]
  - Issue #934: Fix EEPROM write issue on AVR-Ex and AVR-Dx family [#948]
  - Add code to initialize NVMCTRL_CTRLB.FLMAP in new module flmap-init.S enhancement [#947]
  - Add AVR-Ex devices enhancement [#946]
  - Issue 940 runtest [#941]
  - include/avr/io*.h: Update I/O header files enhancement [#938]
  - Issue #936: Provide symbols for exact memory layout. enhancement [#937]
  - Issue #931: Initialize NVMCTRL_CTRLB.FLMAP for Devices that have it. enhancement [#935]
  - Issue #931: Initialize NVMCTRL_CTRLB.FLMAP for Devices that have it. [#933]
  - Issue 929: Remove __ATTR_CONST__ from frexp* prototypes in math.h. [#932]
  - #890 #884: Fix / add entries for ATmega808/9, ATmega1608/9, ATmega3… [#927]
  - #921: Use all h files of $srcdir/include/avr in Makefile.am. enhancement [#925]
  - #892: configure.ac has outdated CHECK_AVR_DEVICE and AM_CONDITIONAL l… [#924]
  - avrxmega3: fix header installation for attiny424 [#921]
  - Rename aux.c to _aux_.c duplicate [#920]
  - iom32u4.h #define USBRF 5 [#919]
  - memory: Allow the use of stdint types [#918]
  - doc: Note attiny9 being supported documentation [#915]
  - Fix __BOOT_SIGROW_READ for some ATtiny [#914]
  - .githud [#908]
  - Extend _delay_loop_2 so it works with AVR_TINY. [#902]
  - Fix inline asm constraints of wdt_enable, wdt_disable. [#901]
  - Use autotools to determine Python command to run mlib-gen.py. [#896]
  - Issue #894: Remove scripts that make binary distributions and RPMs. [#895]
  - Fix issue #892: [#893]
  - Fix some avrxmega3 device names of generated files [#885]
  - .gitignore: Add outputs of ./boostrap [#883]
  - *.py: Use python3 instead of python [#882]
  - Added support for AVR-DA and DB devices [#881]
  - README.md: fix typo in URL [#873]

* Other changes:


*** Changes in AVR-LibC-2.1.0:

* Improvements and additions:

  - Patch #9187 improved the library coverage for the AVR_TINY
    architecture (ATtiny10 and relatives).  In particular, many
    of the functions from <string.h> are now available there.

  - Patch #8729 adds ISR_NOICF and ISR_FLATTEN to <avr/interrupt.h>

* Bugs fixed:

  [#36933] Documentation no longer correctly describes how to declare
  [#41689] add static_assert to assert.h
  [#48898] power_usart3_* functions no more defined in power.h
  [#49020] dtostre() flags documentation error
  [#49447] Example code for uart_putchar() has error in recursive call
  strings for storage in program memory
  [#50439] avr/iom32u4.h does not define PRTIM4
  [#51755] iotn441.h & iotn841.h missing definitions for PUEA[0-7] and PUEB[0-3]
  [no-id] util/eu_dst.h: fix reversed DST decision logic for March and October
  [no-id] util/delay.h.in: add missing return

* New devices supported:

* Contributed Patches:

  [no-id] Define weak symbols for known memory region sizes based on device
  header definitions, starting with fuse region.
  [#8961] Update test script for new simulavr and library layout
  [#8964] Update tests isinf-01.c, signbit-01.c and modf-np.c
  [#9163] New eeprom write block function for xmega using eeprom page write
  [#8729] [avr/interrupt.h] Add ISR_NOICF, ISR_FLATTEN. Fix namespace of identifiers.
  [#8536] Fix a typo within <stdio.h>
  [#8649] small documentation fixes in
  [#9187] [AVR_TINY]: Support 16-bit xtoa functons and more string functions.
  [#9400] Add avrxmega3 multilibs
  [#9659] Update eeprom_is_ready for avrxmega3 devices
  [#9553] Fix some issues in libc/
  [#9864] Use proper float function names and prototypes

* Other changes:


*** Changes in AVR-LibC-2.0.0:

* General:

    This is the first official release supporting AVR-GCC 5 (and above).

* Bugs fixed:

  [#33698] Explicit use of RJMP/RCALL can cause "relocation truncated to fit:
           R_AVR_13_PCREL" linker error
  [#34719] Check for right build compiler
  [#43011] Bug in struct definition of __reg_UCSR1C and __reg_UCSR0C in iom128rfa1.h
  [#43044] memory sections require __attribute__ ((used))
  [#43828] wdt.h: Wrong inline assembler arguments
  [#44140] wdt_disable() macro clobbers prescaller bits
  [#44279] incorrect USB_TRNCOMPL_vect_num in iox64a1u.h, iox128a1u.h
  [#44515] Wrong build option '-mtiny-stack' instead of '-msp8'
  [#44574] Place device-specific libraries in their multilib directory
  [#44869] trunk doesn't work with gcc 5.1.0-RC-20150412
  [#44977] Incorrect PORT_t and CRC_t definitions for ATxmega64A1U and 128A1U
  [#45539] iom32u4.h defines reserved IO address (TIMSK2 (0x70), TIMSK5 (0x73) etc)
  [#45551] Power-save mode not supported for ATtiny167
  [#36303] Wrong hour for EU Summertime
  [#44514] Wrong build option '-mtiny-stack' instead of '-msp8'
  [no-id] TC_EVACT_FRQ_gc was misspelled as TC_EVACT_FRW_gc in some Xmega
          header files
  [no-id] LOCKBITS renamed to LOCK_BITS in Xmega header files as LOCKBITS
          clashes with definition in lock.h. Added missed defines to ADC_CH_MUXPOS_enum.
          Corrected pinmux values in ADC_CH_MUXNEG_enum.
  [no-id] Fix typos and incorrect definitions in header files.

* New devices supported:

  - ATA6616C, ATtiny441, ATtiny841, ATA6612C, ATA6617C, ATA664251, ATmega48PB,
    ATmega88PB, ATA5702M322, ATA5782, ATA5790N, ATA5831, ATA6613C, ATA6614Q,
    ATmega64HVE2, ATxmega8E5, ATxmega32C3, ATxmega32D3, ATxmega32E5

* Contributed Patches:

  [no-id] save & restore rampd register in xmega wdt_enable and wdt_disable
  [#8543] Fix multiple issues with device header files
  [#8557] Proposing to remove device specific xmega macros from sleep.h
  [#8563] Generalize power reduction macros in power.h by removing hard coded device names
  [#8564] Add dwarf debug info alternative, build printf with debug info
  [#8565] Compute and include device header file name from
          __AVR_DEV_LIB_NAME__ as fallback in io.h.
  [#8587] Move device specific functions to libdev.a
  [#8590] WDT enable/disable for devices with CCP
  [#8610] Remove eeprom function name mangling
  [#8716] Enable setjmp/longjmp functions for AVR_TINY architecture
  [#8718] Enable EEPROM memory map only for devices with EEPROM Data Memory
          Mapping Enable bit (EEMAPEN)
  [#8731] Header file for atmega644a
  [#8728] Use __extension__ with long long
  [#8556] Fix atexit.c
  [#8810] Fix LFUSE_DEFAULT for tiny24a/44a
  [#8902] Xmega's PROTECTED_WRITE is incorrect for IO registers whose address
          is more than one byte

* Other changes:

  Overhaul of doxygen documentation.


*** Changes in AVR-LibC-1.8.1:

* Bugs fixed:

  [#31267] misleading header iom128rfa1.h
  [#35197] sleep.h _BV defined as __BV in AT90S8515 section
  [#35226] Online-documentation broken - [...]
  [#35398] assert doesn't work unless stdlib.h is also included
  [#35498] misspelled in <util/setbaud.h>
  [#35539] stdlib.h does not provide EXIT_SUCCESS et al.
  [#35948] iom32u4.h for ATmega32U4 incorrectly defines Timer 2
  [#35971] attiny4313 (2313a) pin-change interrupts PCINT[0...2] vect etc
  [#36053] Declaration of the register USIBR missing for ATtiny2313a/4313
  [#36410] avr/boot.h: poisoned SPMCR for ATmega128
  [#36454] string.h: Error for long long in C90
  [#36581] avr-libc: pgmspace.h is not ANSI compliant
  [#37103] ATtiny5/9/10/20/40 watchdog can't be enabled
  [#37778] _MemoryBarrier() in cpufunc.h error on compile
  [#38135] Install a dummy stdfix-avrlibc.h
  [#38516] Missing TWI and UCSR1D definitions for ATmega16/32 U4
  [#39049] Clock prescaler set and get are missing for TINY architecture
  [#39783] CRC missing definitions and incorrect power macros for xmega D3
  [#40003] Integer type promotion leads to inefficent code in wdt.h
  [#40206] incorrect SP init in startup code for xmegas
  [#40567] Invalid names in iotn13a.h (EEPE/EEMPE/BODS/BODSE)
  [#40569] sleep_bod_disable does not work in attiny13a
  [#40595] iotn2313a.h: wrong fuses definitions for High Fuse Byte
  [#41006] iom328p.h: wrong fuse defaults
  [#41519] wrong SPM_PAGESIZE definition in iotn[48]8.h
  [#42024] build break regarding avrtiny10
  [#42084] wrong LFUSE_DEFAULT in iotn84a.h
  [#42085] HFUSE_DEFAULT not defined for iotn84.h
  [#39779] PCIE0 and PCIE1 defined incorrectly for mega165a and mega165pa devices
  [#38614] dtostrf - wrong behavior or wrong documentation
  [#42957] missing SPMCSR defines in iom328p.h#
  [#41690] Bit definitions for SPMCSR
  [no-id]  XXX_vect_num not consistent io90pwmx.h, iousbxx6_7.h
  [no-id]  Specialize clock_prescale_set/get for mega hvb devices
  [no-id]  Update register and bit definitions for tiny 13a/24a/44a/84a,
           tiny167 and mega328p

* New devices supported:

  - ATmega256RFR2, ATmega2564RFR2, ATmega128RFR2, ATmega1284RFR2,
    ATmega64RFR2, ATmega644RFR2, AT90pwm161, ATA5272, ATA5505, ATA5790,
    ATA5795, ATA6285, ATA6286, ATmega1284, ATmega128A, ATmega164PA,
    ATmega165PA, ATmega168PA, ATmega3250PA, ATmega325PA, ATmega3290PA,
    ATmega32A, ATmega48PA, ATmega64A, ATmega8A, ATtiny1634, ATtiny828,
    ATxmega128A3U, ATxmega128A4U, ATxmega128B1, ATxmega128B3, ATxmega128C3,
    ATxmega128D4, ATxmega16A4U, ATxmega16C4, ATxmega192A3U, ATxmega192C3,
    ATxmega256A3BU, ATxmega256A3U, ATxmega256C3, ATxmega32A4U, ATxmega32C4,
    ATxmega384C3, ATxmega384D3, ATxmega64A3U, ATxmega64A4U, ATxmega64B1,
    ATxmega64B3, ATxmega64C3, ATxmega64D4

* Contributed Patches:

  [#3729] Printf for integers speed up
  [#7212] Add pgm_read_ptr() macros to pgmspace.h
  [#7220] Add UBRR overload functionality to <util/setbaud.h>
  [#7260] Addition to power.h
  [#7485] CRC8-CCITT
  [#7654] include/delay.h: delay_us >255us without decreasing resolution
  [#7826] Add ATMega32u4 support to the led-blinking demo
  [#7909] Adding __volatile__ to __asm__ within pgmspace header
  [#7910] Add missing PCINT2_vect to iotn40.h and update all the
          following vector numbers
  [no-id] correction in xmega wdt_enable and wdt_disable added for xmega
  [#8499] Device ata6289 should be of avr4 architecture
  [no-id] Add RAMSTART, fix RAMSIZE, RAMEND and FLASHEND in device headers
  [#8512] Rename tiny arch to avrtiny to sync with binutils

* Other changes:

  - New macro _PROTECTED_WRITE(): write to Xmega IO registers that are
    protected through the CCP mechanism

  - Add support for scanf() conversion macros for 8-bit data types to
    <inttypes.h>: SCNd8, SCNdLEAST8, SCNdFAST8, SCNi8, SCNiLEAST8,
    SCNiFAST8, SCNo8, SCNoLEAST8, SCNoFAST8, SCNu8, SCNuLEAST8,
    SCNuFAST8, SCNx8, SCNxLEAST8, SCNxFAST8

  - Add time.h package, C standard functions such as mktime() and localtime,
    along with 'ephemera' such as solar declination, time of sun rise and set.

  - Introduce new configure option --with-debug-info=INFO, where INFO
    can be either stabs, dwarf-2, or dwarf-4.  By default, no debug
    information will be generated.

  - Add IO register debug symbols to crt*.o, so debuggers can see the
    per-device defined IO registers (and __eeprom).

  - A number of changes have been applied to make avr-libc more C++
    aware.

*** Changes in AVR-LibC-1.8.0:

* Bugs fixed:

  [#17815] Configure does not honor --mandir option
  [#23234] Alternate interrupt macro
  [#24861] Interrupt documentation contains extra include
  [#32103] Support for Target-Triplets
  [#32419] Incorrect EEPROM size in header for ATxmega192A3
  [#32650] Missing include in util/delay.h
  [#32675] power_all_enable/disable does not affect timer1 on ATmega164P
  [#32698] power.h has additional endif that will break the build
  [#32773] stdiodemo source code is broken
  [#32988] Internal compiler error: build_unary_op
  [#33130] twitest.c source code is broken
  [#33230] Sleep modes have incorrect names for ATtiny261/461/861
  [#33238] Wrong _VECTORS_SIZE for mega8U2 et al
  [#33858] in avr/power.h, clock_prescale_set() not defined for mega328
  [#33920] ICR1 incorrectly defined for tiny167
  [#34047] missing math.h include in delay.h
  [#34514] misspelled in math.h
  [#35020] stdint.h: signed types need explicit "signed"
  [#35093] strlcat_P fails for some destinations
  [no-id]  New names for CLKSTA/CLKSEL0/1 for AT90USB82/162
  system when power_all_disable() is used
  [no-id]  util/delay.h would not compile with -ffreestanding

* New devices supported:

* Contributed Patches:

  [#7531] Bad name of bit in TCCR0A : WGM0 instead of CTC0 for ATtinyX61
  [#7362] iom16a.h: USART vectors inconsistently named for ATmega16A
  [#7226] ATMEGA8U2 Patches

* Other changes:

  - The old prog_* typedefs are now deprecated, and are only included
  if requested by the user.  This request is expressed by declaring
  the macro __PROG_TYPES_COMPAT__, either by a #define directive
  before including <avr/pgmspace.h>, or by a -D compiler option.

  - Optimized strlen_P, thanks to Jan Waclawek. Rename strlen_P to be
  __strlen_P and add new strlen_P inline function in header file that
  checks if value is a constant and known at compile time. If not,
  then the new inline function calls __strlen_P as normal.


*** Changes in AVR-LibC-1.7.1:

* Bugs fixed:

  [Atmel: #11793] XMEGA A devices: 4096-cycle DAC refresh interval setting has wrong name
  [Atmel: #12314] Hi-Res(CTRLA) and AWex (FDEMASK)
  [Atmel: #12536] Remove CALCTRL in xmega header files.
  [no-id] Fix wrong vector table size for ATmega168A devices.
  [#29235] power.h - warning: comma at end of enumerator list
  [#30783] Missing prototype in power.h
  [#31270] Stale link to Philips (now NXP) I2C specification/users manual

* New devices supported:

  ATTiny84a
  ATMega16HVB RevB
  ATMega32HVB RevB

* Contributed Patches:

* Other changes:


*** Changes in AVR-LibC-1.7.0:

* Bugs fixed:
  [Atmel: #7159] the memory location of tccr0b is mixed with tccr0a for tiny48/88
  [no-id] Fix CLKPCE bit value to be 7.
  [no-id] inlining failed in call to '_delay_ms': function body not available
  [no-id] malloc() could allocate memory beyond the limits of heap
  [no-id] xmega header file updates.
  [no-id] Enable ATmega128RFA1 in <avr/power.h>
  [no-id] longjmp() writes to EIND register, it is forbidden by AVR-GCC's API
  [no-id] Define _VECTORS_SIZE in iom3000.h
  [no-id] Redefine __tmp_reg__ and __zer_reg__ for AVR TINY.
  [AVR Tools: #9724] Error in ATtiny13A include file, PRR register
  [sourceforge.net: #1836849] Multiplication does not work for AT90USB162
  [sourceforge.net: #1883630] ATmegaXX4 - USART0 and USART1 additional bits aliases
  [sourceforge.net: #1910885] Typo in io90pwm3b.h
  [sourceforge.net: #1913681] Missing INT3 define in io90pwm3b.h
  [sourceforge.net: #1957780] New 'FUSES-support' gives error in c++ files
  [sourceforge.net: #1969436] Wrong flash size for ATmega32U4
  [sourceforge.net: #2010688] ATtiny48 SPSR register bits
  [sourceforge.net: #2012448] ATmega6450 USART Interrupts
  [sourceforge.net: #2016128] Incorrect ATMega32[c1|m1] Header Entries
  [sourceforge.net: #2018957] Wrong SPM_PAGESIZE for mega1284P
  [sourceforge.net: #2033993] User manual: data symbol spec incorrect
  [sourceforge.net: #2305703] iom162.h ASSR bitdef, typo?
  [sourceforge.net: #2411516] Error/Bug in the iotn88.h file
  [sourceforge.net: #2420567] ATmega329P missing in sleep.h
  [sourceforge.net: #2693898] ATmega32U6 missing in power.h
  [sourceforge.net: #2738926] avr/eeprom.h EEGET and EEPUT
  [sourceforge.net: #2812125] ATmega16U4 missing in power.h
  [sourceforge.net: #2913419] Misspelled Structure Element - xmega
  [#3485]  Using float arithmetic without linking with -lm result in incorrect code
  [#19079] sscanf %s eats 1 char too much
  [#19494] sfr_defs.h documentation: Remove references to deprecated macros.
  [#21410] Incorrect use of 16-bit eeprom addresses in devices with 8-Bit address registers
  [#21621] Allow autoconf 2.61
  [#21622] Support building in a subdirectory
  [#21623] boot.h: Use the "z" register constraint
  [#21869] Multiple defines in iotn2313.h
  [#21872] __floatunsisf/undisf incorrectly named
  [#21905] scanf: float conversion ignores the suppression symbol
  [#21906] scanf: float conversion, wrong width count in case of sign or exponent
  [#21931] Wrong fuses defined for the ATMEGA88/168
  [#21935] Typo in avr-ar example avr-as should be avr-ar
  [#21995] pgm_read_xxxx() does not use enhanced LPM instruction
  [#21958] UBRR0/UBRR1 SFR is redefined for ATmegaXX8p and atmega1284p devices
  [#21962] PSYNC1_0 a PSYNC1_1 bits not defined for AT90PWM3B and AT90PWM316 devices
  [#21986] Typo in iotn13.h
  [#22016] Typo in iotn2313.h: SIG_OUTPUT_COPMARE0A
  [#22119] Misleading statement in FAQ
  [#22153] setjmp.o is wrong in libc.a (1.6.1) for avr's with SPH
  [#22240] Add EEPROM Page Size to header files
  [#22276] wdt_reset fails with devices with large WDTCSR addresses
  [#22377] Wrong XRAMEND for some recent ioXXX.h header files.
  [#22387] Missing EIMSK and __EEPROM_REG_LOCATIONS__ in iom168p.h
  [#22390] Unclear note about function pointers
  [#22447] Summary of iom?8p.h header updates needed
  [#22493] Typo in iom1284p.h.
  [#22540] Adding signature bytes to header files
  [#22548] Missing IVCE and IVSEL in iom328p.h
  [#22568] Missing EEPROM_REG_LOCATIONS in iom328p.h
  [#22572] Documentation FAQ example proposal
  [#22642] AT90USB162 and AT90USB82 not supported in <avr/power.h>
  [#22643] math.h c99 incompability
  [#22666] io90pwm3b.h errors
  [#22785] ATMega644P Support Missing from avr/include/avr/sleep.h
  [#22828] eeprom_write_block(): incompatibility in args order
  [#22834] ATmega164P/324P/644P/1284P lack BODS/BODSE bits in MCUCR
  [#22870] Error in wdt.h and ATmega164P
  [#22877] Fuse information wrong for xmega devices.
  [#22878] eeprom_*_word/dword/block cause hang in ATmega256x
  [#23004] Watchdog enable docu only generated for Xmega series
  [#23032] Define PORTxn, PINxn, DDxn bit names in iomxx4.h.
  [#23166] atmega328p does not have SPMEN
  [#23261] AT90USB162 and AT90USB82 missing power_all_[enable,disable]() in power.h
  [#23409] Provide an implementation for strtok()
  [#23546] FAQ documentation symbol seems wrong
  [#23554] Wrong bit values in iom32u4.h
  [#23677] Request for cbrt() and strdup to be added to libc
  [#23703] eeprom write functions optimisation
  [#23774] Using some defines from avr/fuse.h produces warning
  [#23850] ATMega8 does not have MCUSR defined
  [#23871] clock_prescale_set() not available for ATmega32U4
  [#23959] Small typo in deprecated documentation
  [#23969] eeprom_read_byte() throws interrupt EE_READY although EERIE is cleared, controller resets
  [#24207] Example in inttypes.h is wrong
  [#24446] _attribute_ should be __attribute__ (with double underscores)
  [#24762] 1.6.3 wdt.h compile-time bug
  [#24890] Small error in libm source fp_rempio2.S
  [#25048] eeprom.h will not compile as c++ code.
  [#25120] pgm_read_*_far() functions cause incorrect usage of the Z pointer for RAM access in ATxmega series
  [#25131] Incorrect definition of default lfuse bits for ATTiny2313
  [#25261] TWIHSR spelling deviates from XML file in AVR Studio 4.15
  [#25535] Nonexistent bit definitions in iotn88.h/iotn48.h AREFD REFS1 RWWSB SM2
  [#25645] xmega header files broken #defines
  [#25723] Realloc corrupts free list when growing into the next free item
  [#25846] include/avr/power.h:628:1: error: missing binary operator before token "defined"
  [#25925] <avr/boot.h> cannot be included on Xmega devices
  [#25929] boot.h Fuse read not compatible with Tiny48/88.
  [#25930] New IO-Headerfiles missing PXn Portpindefinitions
  [#26188] Wrong or missing definition of SIGNATURE_X in iom644.h and others
  [#26284] boot_lock_fuse_bits_get does not compile under gcc 4.3.X
  [#26308] WDE defined as WDE3 in io90pwm3b.h and io90pwm2b.h
  [#26767] XMEGA GPIO register name discrepancy
  [#26809] Some common math constants missing in math.h
  [#26840] Missing #define in iom32m1.h
  [#26876] include io.h into fuse.h
  [#27201] _WORDREGISTER in xmega headers does not work in C99 mode
  [#27235] malloc: Several things go wrong
  [#27242] realloc: serious error when size shrinks
  [#27243] malloc: small error in comment
  [#27367] RAMSTART missing in elder device header files
  [#27434] Arguments of macros must be protected in parentheses
  [#28575] Minor bug in iousb162.h - missing FUSE_ prefixes
  [#28688] using_tools.dox fails to build due to extra underscore
  [#28756] Bug in AVR-LibC 1.6.7 (power.h for 8-bit AVR)
  [#28812] iotn48.h TWS# bits off by one
  [#28584] iocanxx.h Add word definitions to iocanxx.h
  [#28627] power.h ATMEGA32U2 clock_prescale_set() not available
  [#28901] Xmega header files with missing definitions for GPIO_t and CPU_t
  [#28574] Xmega D ADC struct missing registers
  [#28582] XMEGA A3B, RTC32 not properly supported
  [#28921] pointer to function > 128k flash
  [#29502] literal error in iox128a1.h
  [#29653] PUD bit missing for at90usb82
  [#29950] ATtiny167 SPM_PAGESIZE Discrepancy
  [#30018] Errors in include files
  [#30085] memcpy_P on XMega does not clr NVM.CMD before copy
  [#30104] power.h - Missing "power_usart1_/enable/disable()" functions for ATmega644
  [#30148] XMEGA register discrepancy
  [#30600] Missing processor spec - wdt.h include file
  [#30597] Missing definition for ATmega16/32/64m1/c1
  [#30475] SPM_PAGESIZE is incorrect in io90pwm3b.h and io90pwm2b.h
  [#30552] Missing definition ADCW
  [#30569] ATmega16U4/32U4 wrong bit definition
  [#30669] Improve comment in stdiodemo
  [#30735] bug in example twitest
  [#31086] ATTINY88 RAMEND value not set to correct value in iotn88.h
  [#30363] _delay_xx() functions in <util/delay.h> are broken
  [#31990] PRPSC0 used in power.h for AT90PWM81 instead of PRPSCR
  [#31873] power_aes_enable/disable() are commented in power.h for xmega devices

* Other changes:

  - Added 'avr35' architecture. Now 'MOVW' and 'LPM Rx, Z[+]' instructions
    supported for AT90USB82 and AT90USB162 devices. GCC 4.3 or above is
    necessary to use this.

  - Function vfscanf() is rewriten. The float point version is optimized
    considerably: the expense of a stack was cut by half, and the size of
    function has decreased approximately on 1KB. Opportunities of standard
    and minimal versions are expanded, and their size has remained at a
    former level.

    Briefly:
      . Restrictions of a float point format are eliminated.
      . Conversion '%[' is present in standard version now.
      . The minimal version differs from standard only absence of '%[' conv.
      . The 'hh' type qualifier is added ('char *', C99).
      . The maximal field width is increased up to 255 (65535 in float version).
      . All known bugs are fixed.

    New vfscanf() concedes old in:
      . The size of the minimal and standard versions has increased for old
      branches of compiler (less 4.1) and ancient chips (without MOVW).
      . The maximum quantity of conversions now is limited (255).

  - EEPROM functions are rewriten.  Now they are pure asm functions.  The
    reading of long word or block is speed up.  New functions for 32-bit
    words and floats are added.  The group of 'update' (burn only different
    bytes) functions is added.  A set of Avr-libc bugs are fixed.

  - Added support for XMEGA architectures.

  - The Postscript documentation build has been removed in favour of
    building only the PDF (and HTML and man page) versions.  PDF offers
    the same printing quality as postscript at a smaller file size.
    This also works around a bug in doxygen 1.5.7 where it appears to
    be no longer possible to set GENERATE_HTML = NO.

  - A sleeping BOD API was added to <avr/sleep.h>. This allows you to disable
    the Brown Out Detector (BOD) before going to sleep, thereby reducing
    power even further.

  - The note about signbit() implementation is removed from documenatation.
    The reason is that the GCC can replace it with inline code and the
    nonzero value is unpredictable in such case.

  - Signature API added in <avr/signature.h>.

  - All functions are now placed in the .text.avr-libc section, and the
    floating point functions are placed in the .text.avr-libc.fplib section. This
    allows the user the ability to relocate all avr-libc routines to a different
    address using a custom linker script.

  - The port/pin assignments of the HD44780 LCD controller in the
    stdiodemo example can now be distributed across more than a single
    AVR port.  The only remaining requirement is that all data bits
    are assigned to a single port in ascending order.

  - Added support for avrtiny10 architecture, to support the ATtiny10 Family.

  - Added new headerfile: <avr/cpufunc.h>; currently contains _NOP() and
    _MemoryBarrier().

  - The twidemo can now optionally address 24C32 and larger EEPROMs
    that require 16-bit word addressing.

  - Add a "memory barrier" to the cli() and sei() macros.


* New devices supported:

  + ATxmega64D3
  + ATxmega128D3
  + ATxmega256D3
  + ATxmega192A3
  + ATxmega128A1
  + ATxmega64A1
  + ATmega32M1
  + ATmega32C1
  + ATmega32U4
  + ATtiny167
  + ATtiny13A
  + ATmega32U6
  + AT90SCR100
  + ATtiny87
  + ATxmega32A4
  + ATmega16M1
  + ATmega64C1
  + ATmega64M1
  + ATA6289
  + AT90PWM81
  + ATmega128RFA1
  + ATxmega32D4
  + ATxmega16A4
  + ATxmega16D4
  + ATmega16U4
  + ATmega8U2
  + ATmega16U2
  + ATmega32U2
  + ATxmega192D3
  + ATtiny2313A
  + ATtiny4313
  + ATtiny24A
  + ATtiny44A
  + ATtiny261A
  + ATtiny461A
  + ATtiny861A
  + ATmega644PA
  + ATmega88PA
  + ATmega16A
  + ATmega64HVE
  + ATmega169PA
  + ATmega649P
  + ATmega324PA
  + ATmega16HVA2
  + ATmega16HVB
  + ATmega48A
  + ATmega88A
  + ATmega168A
  + ATmega328
  + ATmega164A
  + ATmega324A
  + ATmega644A
  + ATmega165A
  + ATmega169A
  + ATmega645A
  + ATmega6450A
  + ATmega649A
  + ATmega6490A
  + ATmega6490P
  + ATmega645P
  + ATmega6450P
  + ATmega329PA
  + ATxmega128A1U
  + ATxmega64A1U
  + ATtiny4
  + ATtiny5
  + ATtiny9
  + ATtiny10
  + ATtiny20
  + ATtiny40
  + ATtiny84A
  + ATmega325A
  + ATmega3250A
  + ATmega329A
  + ATmega3290A
  + M3000

* Optimized functions:

   eeprom_read_block
   eeprom_read_dword
   eeprom_read_word
   eeprom_write_block
   eeprom_write_dword
   eeprom_write_word
   strtod
   setjmp
   sqrt   (and callers: acos, asin and hypot)
   sin, cos, tan:  minor in space
   strlcat, strlcat_P
   strlcpy, strlcpy_P
   strtok, strtok_r

* Contributed Patches:

  [#6194] Twitest updated to handle larger EEPROM devices
  [#6352] Far pointer library
  [#6500] Reentrant code faq
  [#6517] Pgmspace with float support
  [#6555] malloc improvement
  [#6649] sqrt.S in libm changes
  [#6690] Shorten calculation of dallas 1-wire crc
  [#6718] Optimize the EEPROM functions
  [#6720] FAQ update. Add EEPROM section, baud rate section. Correct spelling.
  [#6791] Minor fixes to stdio.h documentation
  [#6878] eewr_byte.S update for patch #6718
  [#6891] Add XMega software reset to the FAQ section on software reset
  [#6895] Improved malloc behaviour when expanding used area
  [#6897] Allow <util/setbaud.h> to be used with assembler source

* New functions:

   cbrt
   eeprom_read_dword
   eeprom_read_float
   eeprom_update_block
   eeprom_update_byte
   eeprom_update_dword
   eeprom_update_float
   eeprom_update_word
   eeprom_write_dword
   eeprom_write_float
   memccpy_P
   strdup
   strtok
   strtok_P
   strtok_rP
   strlen_PF
   strnlen_PF
   memcpy_PF
   strcpy_PF
   strncpy_PF
   strcat_PF
   strlcat_PF
   strncat_PF
   strcmp_PF
   strncmp_PF
   strcasecmp_PF
   strncasecmp_PF
   strstr_PF
   strlcpy_PF
   memcmp_PF


*** Changes in AVR-LibC-1.6.0:

* Main changes from avr-libc 1.4 to 1.6:

  + The fplib/math library is completely rewritten. Now features of the IEEE
  754 standard are supported all: negative zero, subnormals, Infs and NaNs.
  It concerns both to base operations (arithmetic, comparison...), and to
  all functions. Speed of performance is increased, sometimes considerably.
  A number of mistakes (not reflected in the Bugs) which led severe losses
  of accuracy for some arguments is corrected. A number of new functions is
  added. It is necessary to note, that the new library concedes old under
  the charge of flash memory a little.

    Incompatibilities:

    - Conversion from float to long (make similar to GCC/x86):  in case if
    overflow was or if input is NaN return 0x80000000 for signed result and
    return 0 for unsigned result. Negative input (not too big in absolute
    value) is permissible for cast to unsigned long, for example: (unsigned
    long)(-1.0) returns ULONG_MAX.

    - The signbit() function: return 1 as nonzero value (make similar to
    builtin GCC).

    - Make frexp() similar to GCC/x86 in case of nonfinite arg: write 0 by
    exponent pointer. Early Avr-libc's frexp() skips exponent storing in this
    case. Make the NULL a legal address to skip a storing.

  + Functions of numbers to ascii conversion are completely rewritten:
  dtostre(), dtostrf() and printf() family. They more do not use float point
  operations. Speed of int/float to ascii has increased in some times. For
  printf() the stack usage is reduced.

  + Test suite is added to the Avr-libc project.

  + A few new util's headers: util/atomic.h, util/setbaud.h .

* Bugs fixed:

  [no-id]  iscntrl() return true for some values from 0x80 to 0xff.
  [no-id]  Fix the examples installation for non-doc builds.
  [no-id]  Fix the spelling of the OCR1A/B registers in ATtinyX4 devices.
  [no-id]  LED1/2 don't work in the largedemo on an ATmega16.
  [no-id]  Not defined SPM_PAGESIZE for ATtinyX4/X5/X61 and ATtiny2313 devices.
  [no-id]  Typo in iomxx0_1.h: PRUSART3.
  [no-id]  Make include/avr/sfr_defs.h -Wundef safe.
  [no-id]  Make include/avr/eeprom.h -Wundef safe.
  [no-id]  Fix the timing of the HD44780 driver in the stdiodemo.
  [no-id]  Fix the sleep mode definitions for the ATtiny2313.
  [no-id]  Exclude 64-bit types for -mint8.
  [no-id]  Make documentation build work with doxygen 1.5.x
  [#1929]  -Inf not detected
  [#11511] NaN not generated correctly by division library
  [#11820] dtostre: wrong output with percision =3
  [#13330] NaN is recognized not always
  [#15161] util/delay.h misses inline keyword (regression)
  [#15193] incorrect definition of IVSEL bit in MCUCR register
  [#15266] Function ldexp incorrectly processes overflow and underflow cases.
  [#15494] Compile warning and errors if compiler flag -Wundef flag specified
  [#15512] Bootloader macros not interrupt safe.
  [#15519] AT90CAN* processors incorrectly identified as "AT90S family"
  [#15522] Typo in iotn2313.h vector table
  [#15559] Wrong macro for boot_page_write(address) and ATmega128
  [#15574] unneeded compatibility break
  [#15595] GPIOR0 misspelled for ATtiny25/45/85
  [#15732] interrupt.h: ISR() incompatibility with gcc 3.4.5
  [#15890] missing /devtools/gen-avr-lib-tree.sh
  [#16039] Names in Pxy (i.e. PA0) style of ports pins for some devices are
           not defined.
  [#16125] HD44780 data bit assignment restrictive
  [#16260] _crc16_update lacks C equivalent
  [#16411] Add the 'used' attribute to all interrupt service routine macros.
  [#16434] EMPTY_INTERRUPT has no misspelled vector checking
  [#16441] eeprom.h should use __asm__
  [#16868] depricated.h: outp() arguments order misprint
  [#17068] wdt.h file: __AVR_ATmeg324P__ spelling mistake
  [#17470] Add API for CLKPR register.
  [#17551] Update documentation to point to issues with gcc4.1
  [#17591] /avr-libc/libm/fplib/fp_split.S error return will fail for
           3-Byte PC devices
  [#17608] Add ISR_ALIAS() to avr/interrupt.h
  [#18115] online documentation typo/bug avr/boot.h
  [#18373] Bugs in Inline ASM documentacion
  [#18385] SPM_PAGESIZE wrong value for ATmega164p and ATmega324p
  [#18509] strtod.S crashes due to stack problem with atmega 2560
  [#18662] rand() keeps returning the same value if seeded with 0
  [#18686] AT90USB**** devices are absent in interrupt-verctor-names table
  [#18688] vfscanf and vfprintf don't use malloc
  [#18726] the dtostrf function description is missing in AVR-Libc's webpage
  [#18903] ATmega644 register definitions for SPI and PRR (datasheet vs.
           iom*.h)
  [#18915] PWM1X Bit missing for ATtiny261/461/861
  [#18964] USART definitions *wrong* in iocanxx.h
  [#18994] minor optimization possible to stdlib functions isspace(),
           isprint(), and islower()
  [#19009] Make <util/delay.h> issue a warning when optimizations are turned off
  [#19050] gcrt1.S should call main rather than jumping to it
  [#19060] PCMSKx registers transposed in header for attinyX61
  [#19445] _malloc_heap_end does not follow _heap_end on m2561
  [#19495] <avr/interrupts.h> documentation: fix inclusion of cli and sei macros
  [#19496] Add documentation: how to build toolchain for Windows.
  [#19650] avr-libc: wrong named bit in SFR of AT90PWMx
  [#19666] AT90PWMx: Another patch for the include file (missing SFR)
  [#19669] Need function to read signature row
  [#19686] alloc declaration missing
  [#19841] Error building 1.4 HEAD: undefined reference to 'exit'
  [#20248] FAQ#3: clarify which registers are safe to be used
  [#20276] power.h missing ATmega644Ppower_XXX_[en/dis]able() macros
  [#20435] Bit name definitions for AT90PWM3
  [#20530] Bug in sample code for early wdt disable
  [#20650] Missing description of AVR specific C-preprocessor macros
  [#20682] Bad bit name in avr/io2313.h - Sugestion
  [#20843] Mega 2561 library
  [#21174] assembly error with targets at90s1200, attiny11, attiny12,
           and attiny28
  [#21183] Fix Program Space example code.
  [#21204] iotnx61.h PRR bits incorrect
  [#21228] Missing 3rd clause in BSD license in documentation pages
  [#21299] Duplicate register address in iotn48.h.
  [#21411] Typographical error in 'iotn13.h'
  [#21432] Incorrect timer interrupt handler names for ATtiny45
  [#21434] Bit name definitions for AT90CANxxx
  [#21444] Undocument -minit-stack
  [#21484] Documentation build for avr/version.h does not susbstitute autoconf
           macros
  [#21749] AT90PWM316: _VECTORS_SIZE should be 128
  [#21691] iomx8.h-> IVSEL and IVCE should not be available for ATmega48
  [#21743] AT90PWM316 missing PSOC1 bit definitions
  [#21626] Incorrect Bit Definition for ADC14 and ADC15 Digital Input Disable
  [#21521] incorrect bit definitions in iotnx61.h
  [#21840] RAMEND wrong for ATmega48P/88P/168P

* Other changes:

  - New Power Management API in <avr/power.h>. This provides C language
    macros to manipulate the Power Reduction Register(s) and the System Clock
    Prescaler register across multiple processors.

  [patch #4611] sleep.h sleep_mode() not interrupt safe

  - The simple demo has been modernized a bit.  Documentation now
    generally refers to the ATmega8 rather than the AT90S2313, and
    the #ifdef spaghetti has been moved out into iocompat.h.

  - A new demo project ("largedemo") has been added.  It extends
    the simple demo by adding some controls, and thereby touches
    a good number of avr-libc concepts.  It has originally been
    written for the ATmega16, but can also be run on an ATmega8
    or a member of the ATmegaX8 family, as well as on an ATtiny2313.

  - Another demo project ("stdiodemo") has been added.  It
    demonstrates the setup of the standard IO facilities using
    a practical small application.

  - The demo projects now install their source code as part of
    the documentation tree.

  - The simple demo has been ported to ATmega8515, ATmega8535,
    ATmega164P, ATmega165, ATmega169, ATmega324P, ATmega325,
    ATmega3250, ATmega329, ATmega3290, ATmega640, ATmega644,
    ATmega644P, ATmega645, ATmega6450, ATmega649, ATmega6490,
    ATmega1280, ATmega1281, ATtiny2313, ATtiny24, ATtiny25, ATtiny26,
    ATtiny261, ATtiny44, ATtiny45, ATtiny461, ATtiny84, ATtiny85,
    ATtiny861.

  - More overhaul of the demo documentation, don't use the "squid"
    cable for the largedemo as it is not part of the STK500.

  - Integrate a copy of the license file into the documentation.

  - Include an alphabetical index of all globals (functions,
    macros, types, variables) into the documentation.

  - Added 'avr25' architecture. Now 'MOVW' and 'LPM Rx, Z[+]' instructions
    supported for AT86RF401, ATtiny13, ATtiny2313, ATtiny24, ATtiny25,
    ATtiny261, ATtiny44, ATtiny45, ATtiny461, ATtiny84, ATtiny85 and
    ATtiny861 devices. GCC 4.2 or above is necessary to use this.

  - Add the benchmark page.

  [patch #5756] New atomic.h header file (added as <util/atomic.h>)

  [patch #5343] Add a util/setbaud.h "helper" file

  [patch #6236] Improving _delay_us and _delay_ms

  [patch #5644] New interrupt.h header file

* New devices supported:

  + ATtiny24
  + ATtiny261
  + ATtiny44
  + ATtiny461
  + ATtiny84
  + ATtiny861
  + ATmega406
  + ATmega169 Rev. F
  + AT90USB82
  + AT90USB162
  + AT90USB646
  + AT90USB647
  + AT90USB1286
  + AT90USB1287
  + ATmega48P
  + ATmega88P
  + ATmega164P (renamed from ATmega164)
  + ATmega168P
  + ATmega324P (renamed from ATmega324)
  + ATmega328P
  + ATmega644P
  + ATmega1284P
  + ATmega165P
  + ATmega169P
  + ATmega2560 [patch #4461]
  + ATmega2561 [patch #4461]
  + ATmega325P
  + ATmega3250P
  + ATmega329P
  + ATmega3290P
  + AT90PWM1
  + ATmega8HVA
  + ATmega16HVA
  + ATmega32HVB
  + AT90PWM216
  + AT90PWM316
  + ATtiny43U
  + ATtiny48
  + ATtiny88
  + AT90PWM2B
  + AT90PWM3B

* New functions:

   strstr_P (Contributed by Werner Boellmann)
   round
   lround
   lrint

* Optimized functions:

   dtostre

*** Changes in AVR-LibC-1.4.0:

* Major API changes:

  - The INTERRUPT() macro has been deprecated, and it will be
    removed in a future version.  Use __attribute__((interrupt))
    explicitly if this functionality is really needed.

  - A new ISR() macro has been added, and is now the preferred
    for to introduce an interrupt service routine.  It is
    equivalent to the old SIGNAL() macro, which might become
    deprecated in a future version.

  - A new header file, <compat/deprecated.h> has been established.
    Its purpose is to collect deprecated items from older versions of
    the library, starting out with the enable_external_int(),
    timer_enable_int(), and INTERRUPT() macros/functions, as well as
    the old obsoleted inp/outp/sbi/cbi macros.

  - A new include file subdirectory named "util/" has been created.
    The files <compat/twi.h>, <avr/crc16.h>, <avr/delay.h>, and
    <avr/parity.h> have been moved into the new util/ subdirectory.

  - A new set of interrupt vector names has been added, closely
    matching the names given in the datasheet, and more compatible to
    other compilers available for the AVR platform.  The table of
    interrupt vector names in the documentation is now automatically
    generated, and explicitly mentions the MCU type for each vector
    name.

  - The standard IO facilities API has been enhanced

    . The backend functions put and get that are passed to fdevopen()
      during the setup of a stream now take the stream itself as an
      additional argument.
      By defining the macro __STDIO_FDEVOPEN_COMPAT_12 before
      including <stdio.h>, an fdevopen() function prototype will be
      declared that is backwards-compatible with avr-libc version
      1.2 and before.
    . It is possible to tie user data to a stream using
      fdev_set_udata(), and to retrieve them using fdev_get_udata().
      Together with the additional argument to the backend functions,
      these functions can now e.g. keep track of internal user state,
      or distinguish two different devices using the same backend
      function.
    . The get backend function can now return _FDEV_EOF to indicate an
      end-of-file condition, in addition to _FDEV_ERR for an error
      condition.  This will affect the internal state that can be
      queried using the standard feof() and ferror() functions.
    . A new macro fdev_setup_stream() is provided to setup a
      user-supplied stream without the need to call fdevopen(), and thus
      without requiring malloc().  A similar macro FDEV_SETUP_STREAM()
      exists that can be used to initialized a FILE object.  The
      floating-point implementations of vfscanf() and vfprintf() now
      allocate their conversion buffer on the stack, so they do not need
      malloc() anymore either.

  - An API has been added to track the library version number.  See the
    documentation of the new header file <avr/version.h>.

* Bugs fixed:

  [#3573] Make local symbols in .S files truely local
  [#12324] overview: boot_page_write_safe, etc.
  [#12333] Standard requires libstdc to define vprintf and vscanf
  [#12495] about Busy-wait delay loops(document)
  [#12496] about set_sleep_mode() and tiny26/tiny2313
  [#12735] No support for AT94K devices in sleep.h
  [#12739] Gcc assumes that target libc provides ffs function
  [#12775] Possible Bug in sscanf on string end
  [#13340] Math lib documentation/lib mismatch
  [#13557] small typo in avr-libc-user-manual-1.2.3
  [#14224] _delay_ms() not inlining if called more than once in a unit
  [#14241] 'eeprom_is_ready' is not compiled with ATmega48
  [#14262] avr-libc documentation error about .init sections
  [#14266] use __extension__ in avr-libc header files
  [#14327] wdt_disable() missing a cli
  [#14378] EEPROM library d'not support at86rf401 device
  [#14380] configure/make work only in source directory
  [#14433] Improve documentation of <avr/delay.h>
  [#14486] some macros from boot.h doesn't compile correctly
  [#14503] strnlen_P is wrong with classic AVRs
  [#14798] several IO registers definition issue in header files
  [#14852] fp pow function broken for negative x

* Other changes:

  [patch #3592] speedup tanh function in libm
  [patch #3750] Allow passing user data to stdio fdevopen() get and
                put methods.  (This is part of the API changes
                mentioned above.)
  [patch #3780]	<assert.h> header
  [patch #3781] add dummy fflush() to <stdio.h>
  [patch #3782] modernize <stdint.h>
  [patch #3912] Fix ctype.S linker error due to asm branches out
                of range
  [patch #3925] Dallas iButton 8-bit CRC
  [patch #4087] C99 conformal headers stdint.h and inttypes.h
  [patch #4505] Unified interrupt vector names in header files
  [patch #4557] Adds to the fplib usage of MUL instruction
                in group avr4; avr5 devices
  [patch #4608] rpm spec file update
  [patch #4622] unify doc file location in rpms

  - Update the build system to recent versions of autoconf/automake;
    the old "doconf" and "domake" scripts are gone now, "reconf" has
    been renamed to "bootstrap".
  - Update the documentation system to doxygen >= 1.4.1.
  - Major overhaul of the documentation, new layout of the HTML pages,
    several clarifications and additions.
  - Add support for the following new devices (depending on the ability
    of the compiler/binutils to handle them):
    . AT90CAN32/64
    . AT90PWM2(B)/3(B)
    . ATmega329/3290/649/6490
    . ATtiny25/45/85
    . ATmega164/324/644
    . ATmega640/1280/1281
  - The library is now compiled with -Os for avr3 and avr5 MCUs (i.e.
    for those with > 8 KB of ROM); used to be -O3 before.

* New string functions. Contributed by Dmitry Xmelkov.

  ffs
  ffsl
  ffsll
  _FFS (macro)

* Optimized functions.

  misc/itoa
  misc/ltoa
  misc/utoa
  misc/ultoa
  stdlib/longjmp
  string/memchr
  string/memccpy
  string/strchr
  string/strrchr
  string/strsep
  string/strstr

*** Changes since AVR-LibC-1.2.4:

* Bugs fixed:

  [no-id]  EEPROM handling not working for AT90CAN128 ATmega48 ATmega88
	   ATmega165 ATmega168 ATmega169 ATmega325 ATmega3250 ATmega645
	   ATmega6450
  [#12646] strtod returns error for valid input (patch#4137)
  [#13341] Remove ADHSM bit from header files.

* Other improvements:

  [patch#4189] Document replacement for sbi/cbi instructions

* boot.h: implement boot_lock_fuse_bits_get() plus macros for the
          respective addresses (low/high/ext fuse, lock bits)


*** Changes since AVR-LibC-1.2.3:

* Bugs fixed:

  [no-id]  Work around a bug in gas that made the weak symbol __stack
           fixed inside gcrt1.S (since the assembler already inserted
           its value).
  [no-id]  Modify the doxygen build system to cope with artefacts from
           recent versions of doxygen and (pdfelatex-based) LaTeX.
  [#12033] macros.inc need to be protected from multiple inclusion.
  [#12040] overview: sbi in FAQ
  [#12134] ADC register name definitions
  [#12422] Add new bit definitions for LCDCCR register in iom169.h.
  [#12448] Fix bit definition for SJW0 in iocan128.h
  [#12785] Fix documenation for log10() function in math.h.
  [#12955] Signal name misprints: SIG_COMPERATOR in iom169.h,
           SIG_EPROM_READY in iotn26.h
  [#12993] Signal "__EICR" redefined warning ATmega8
  [#13290] avr/io.h EEAR def is flawed for the Mega48
  [#13327] Fix bit definition for UCSZ02 in iom325.h, iom3250.h,
           iom645.h, iom6450.h
  [#13678] The _wdt_write(value) macro in wdt.h doesn't work with
           the ATmega325.(also with ATmega3250, ATmega645, ATmega6450,
           ATmega165).

* demo.c extended for ATmega16

*** Changes since AVR-LibC-1.2.2:

* Bugs fixed:

  [#11987] sscanf parsing problem : leading zero ignored in %u

*** Changes since AVR-LibC-1.2.1:

* Bugs fixed:

  [#11805] Fix call to __fp_cosinus in sin().
  [#11817] Replace SYSCLK with F_CPU in twitest example.
  [#11868] realloc doesn't work correctly on block at end of freelist
           when growing
  [#11898] Change optimisation level for building printf libraries to -Os.


*** Changes since AVR-LibC-1.2.0:

* Bugs fixed:

  [no-id]  Prefix all internal global symbols in libm with __fp_ so
           they do not collide with the application namespace.
  [#4101]  setjmp/longjmp destroy changes in global registers.
  [#11479] Add missing pin definitions for iotn16.h.
  [#11486] Put the port bit defintions back in for mega16.
  [#11494] strtol() return wrong value in the underflow case
  [#11505] Remove doxygen comment about the deprecated inp/outp items.
  [#11510] Abstract the change enable bit in wdt.h for mega32.
  [#11522] Rewrite wdt_disable() to match datasheet algorithm.
  [#11684] realloc overwrites first to bytes of memory block when shrinking
  [patch #3618] Optimization strtol(), a little (related to bug #11494).
  [#11732] Update doc/examples/progmem.c to use the latest API.

* Extend stdio and pmstring APIs:

Implement patch #3516: printf: Handling of argument strings from
program memory

The %S format can now be used to print strings that are located in
program-space memory (aka. ROM).

As a prerequisite for this, the function strnlen_P() has been added
which is similar to strnlen() except that it takes a pointer to a
program-space string.

*** Changes in AVR-LibC-1.2:

* Bugs fixed:

  [no-id] Fix TICIE1 value in usb header files.
  [no-id] Fix bug introduced in fix for bug #7802 (missing parens).
  [no-id] Move ATtiny2313 and ATtiny13 from avr4 to avr2 (by now).
  [#2143] malloc() routines chunk smaller than requested
  [#5454] Inline functions results in undefined reference when optimize level 0
          is used.
  [#5799] error(?) in iom162.h
  [#2233] Documentation issues with inline asm
  [#6352] Sleep mode for ATmega162, ATmega161, and ATmega8515
  [#7469] "Problem" by using the library function "boot_lock_bits_set"
  [#7556] printf and friends improperly handle non-null terminated strings when
          a %s argument has a precision.
  [#7802] vfscanf problem with unsigned long (patch #2554)
  [#7989] dtostrf() destroys string pointer registers?
  [#8119] _wdt_write macro in wdt.h doesn't work with ATmega169
  [#8391] Fuse mask in boot.h wrong?
          NOTE: boot_lock_bits_set() was broken. Please see the new
          documentation for examples of how the new version works.
  [#8452] some SFR and bit names in iom169.h are incorrect
          NOTE: Where possible, the old names are retained to avoid breaking
          existing code, but the OCR1A and OCR1B names where just plain wrong
          so they have been changed and the incorrect names (OCRA1 and OCRB1)
          are undefined.
  [#8649] sfr_defs.h: missed _SFR_BYTE() in bit_is_set/clear
  [#9345] Zero-Padding on vfprintf
  [#10150] Update release versions compatible with avr-libc and instructions.
  [#10489] Sleep mode for atmega48/88/168 family
  [#10733] Fix bit identifer ADFR to ADATE in mega64.
  [#10828] Fix licenses on files to have same BSD license.
  [#11242] Add the EEARH register definition for the mega48.
  [#11275] fdevopen() should document its use of malloc()
  [#11315] Add USART* signal names to match datasheet for mega32 and mega16.
  [#11405] Add USART* signal names to match datasheet for mega128.
  [#11418] Add PRR register and bit definitions for mega169.
  [#11425] sleep.h missing semicolon

* Remove deprecated items:
  + obsolete headers from the base include directory (moved to the avr/
    subdirectory long ago)
  + deprecated macros and functions from
    . <avr/eeprom.h> (eeprom_rb, eeprom_rw, eeprom_wb),
    . <avr/io.h>  (cbi, sbi, inb, outb, inw, outw, inp, outp, BV),
    . <avr/pgmspace.h> (PRG_RDB).
  + . <avr/timer.h> removed completely.

* Moved header files:

  + <avr/ina90.h> moved to <compat/ina90.h>
  + <avr/twi.h> moved to <compat/twi.h>

* New devices supported:

  + ATmega165
  + ATmega325
  + ATmega3250
  + ATmega645
  + ATmega6450
  + ATmega48
  + ATmega88
  + ATmega168
  + ATtiny13
  + ATtiny2313
  + AT90CAN128

* Pin names for ports are now consistent for all devices.

* dtostrf() now uses movw where possible

* realloc() has been implemented.

* Extend pgmspace API.

The pgmspace API has had the following macros added to allow accessing of
unsigned 32-bit values:

  pgm_read_dword_near
  pgm_read_dword_far
  pgm_read_dword

* Change boot API.

The boot API internals have changed such that it is not compatible with the
1.0.x API.

These macros have been changed so that they no longer wait for SPM and EEPROM
operations to complete. It turns out that doing those checks all the time is
not needed and tends to bloat the code. Removing the checks allows you to
write more compact code (see the example in avr/boot.h).

  boot_page_fill
  boot_page_erase
  boot_page_write
  boot_rww_enable
  boot_lock_bits_set

If you want the old behaviour (1.0.x compatible), use these new macros:

  boot_page_fill_safe
  boot_page_erase_safe
  boot_page_write_safe
  boot_rww_enable_safe
  boot_lock_bits_set_safe

* Extend eeprom API.

New macro:
  eeprom_busy_wait

* Extend crc16 API.

New functions:
  _crc_xmodem_update
  _crc_ccitt_update

* Extend stdio API.

New functions:
  vfprintf_P
  vfscanf_P
  vsprintf
  vsprintf_P
  vsnprintf
  vsnprintf_P

* Extend malloc API.

Implement realloc().

* Extend delay API (<avr/delay.h>).

Implement inline functions for specifying delays in microseconds, or
milliseconds directly (based on the macro F_CPU specifying the CPU
clock frequency).

* Documentation changes:

  + Use newer Doxygen.
  + Many fixes and added documentation.
  + Unix-style man pages are generated now when doc generation has been
    enabled in ./configure

* Optimize slightly strtol and strtoul functions.

* Unified copyright.

All of the avr-libc files are now distributed under a single license.
All of the authors of the files agreed to this step.  The new license
is a 3-clause simplified ``BSD-style'' license which is believed to be
fully compatible with the GPL on one hand, yet imposes as minimal
restrictions as possible for any kind of commercial use in
applications based on avr-libc.

To build the documentation, doxygen-1.3.4 or newer is strongly recommended.

*** Changes in AVR-LibC-1.0:

* Move source to cvs repositiory at http://savannah.gnu.org/projects/avr-libc

Anonymous cvs access to the source is now available. There is also a mailing
list set up for discussion of development of avr-libc.

* License changes.

All the files in the project now are covered by a modified BSD license. This
allows royalty free use of the library in commerical products. All of the
public domain files in the project have been switched to the new license and
copyright given to the contributors of the files.

There were some files taken from GNU GPL'd projects which were removed from
avr-libc to simplify the licensing. The removed files only supplied alternate
implementations, so nothing was lost by their removal.

* Requires latest binutils and gcc

Marek did some fairly major work with binutils and gcc to make adding support
for new devices easier. His changes in those tools required changes to
avr-libc which make it incompatible with older versions of binutils and gcc.
Gcc versions >= 3.3 and binutils versions >= 2.13 are required.

* New malloc implementation.

Joerg Wunsch has supplied an improved malloc implementation which is less
prone to fragmentation.

* Documentation!

Joerg Wunsch and Ted Roth and have been working on using the doxygen program to
embed documentation comments into source code. Additionally, Harald Kipp's
inline asm cookbook and Rich Neswold's Avr Tools document have been merged into
the user manual. The goal is to have a single place for all the documentation
a user would need to get started developing for AVR microcontrollers using
the GNU development tool chain.

The latest documentation is available online at
  http://www.freesoftware.fsf.org/avr-libc/

* I/O registers accessible directly in C expressions

You can now do this in your code:
  PORTA |= 0x02;

See the "Special Function Registers" documentation for details. This method is
preferred over the use of the deprecated inp(), inb(), inw(), outp(), outb()
and outw() functions.

* New devices supported

mega128
mega169
mega16
mega32
mega64 [untested]
mega8515 [untested]
mega8535 [untested]
tiny26
76c711
43usb320
43usb355
86rf401

* Improved trigonometrical functions:

Reiner Patommel provided complete rewrites for asin(), atan() and atan2()
that feature a better (for some argument ranges even much better)
accuracy than the previous versions.  Note that since acos() uses asin(),
it also benefits from this.

* Incompatibilities with previous version.

The arguments for outb()/outw() have been reversed.
  (value,port) -> (port,value)

* New pgmspace.h API.

Changed function names and added new functions to read the Program Space
FLASH. Added new functions to read 16-bit (word) values. The new API should
also clear up problems with reading data from devices with > 64K of FLASH.

The API now includes:
pgm_read_byte       (maps to the *_near function below)
pgm_read_word       (maps to the *_near function below)
pgm_read_byte_near
pgm_read_word_near
pgm_read_byte_far
pgm_read_word_far


* New bootloader support API.

#include <avr/boot.h>

This provides bootloader support functions to those processors that have
builtin bootloader support.

* inb / outb / inw / outw / cbi / sbi macros are deprecated.

* New string functions and optimized string functions.

strlcpy   (optimized)
strlcat   (optimized)
strsep    (new)
strtok_r  (new)
strlcat_P (new)
strlcpy_P (new)
strncat_P (new)

Contributed by Reiner Patommel with some work on strlcpy, strlcat by
Eric Weddington.

* New eeprom functions by Artur Lipowski <LAL@pro.onet.pl>

eeprom_write_word
eeprom_write_block


*** Changes up to AVR-LibC-20020203:

See the ChangeLog file up to 2002-02-03 for details.