IAR Information Center for STM8

• Important information
• New features
• Known problems
• Program corrections
• User guide corrections
• Miscellaneous
• Release history

Important information

• Read the IAR C/C++ Development Guide for STM8 for detailed information about this product component.

New features

• None

Known Problems

• Struct assignment does not work for objects in huge memory that cross 64-Kbytes section boundaries.

• Some IAR C language constructs relating to inlining and absolute symbols are not represented correctly in the assembler language listings, leading to list files that cannot be assembled.

• The EEC++ templates std::less, std::less_equal, std::greater, and std::greater_equal, as well as the std::string methods append, assign, insert, and replace that take a pointer argument do not take the extended address byte of __far pointers into account, which could lead to unexpected behavior.

Program Corrections

• [EWSTM8-703] An incorrect optimization removes a required load instruction.

User guide corrections

• Summary of extended keywords, page 299
  Extended keyword: __ro_placement
  Description: Places const volatile data in read-only memory
  
  Descriptions of extended keywords, page 304
  __ro_placement
  Syntax: See Syntax for object attributes, page 298.
  Description: The __ro_placement attribute specifies that a data object should be placed in read-only memory. There are two cases where you might want to use this object attribute:
  

  • Data objects declared const volatile are by default placed in read-write memory. Use the __ro_placement object attribute to place the data object in read-only memory instead.
  • In C++, a data object declared const and that needs dynamic initialization is placed in read-write memory and initialized at system startup. If you use the __ro_placement object attribute, the compiler will give an error message if the data object needs dynamic initialization.
  
  You can only use the __ro_placement object attribute on const objects.
  
  In some cases (primarily involving simple constructors), the compiler will be able to optimize C++ dynamic initialization of a data object into static initialization. In that case no error message will be issued for the object.
  
  Example:
  

  __ro_placement const volatile int x = 10;

  
  

Miscellaneous

• Workaround for the hardware bug "Unexpected result when DIV/DIVW instruction used in ISR"
  If there is a DIV or DIVW instruction in the ISR or there is a call to at least one function the compiler automatically inserts a workaround as:
  

  push cc
  pop a
  and a,#$BF
  push a
  pop cc

  Note: If there is no DIV and no DIVW instruction and no call to any function the workaround is not implemented.
  You can globally disable the workaround from the command line with the option --disable_hardware_workaround DIV_ISR.
  You can also disable the workaround for individual interrupt service routines using the new function object attribute __no_div_workaround.
  See hardware errata for more information.
  

Release history

V3.10.1 - 2017-06-30

Program corrections

• [EW26254] Correct C code can cause an internal error in the compiler after an inline assembler statement has resulted in an error.

• [EW25931], [EW26300] The linker optimization to merge duplicate sections (--merge_duplicate_sections) can sometimes incorrectly merge non-equivalent sections.

New Features

• Improved code generation and optimization
  The compiler generates smaller and faster code for certain source program constructions.

• Extended functionality in C-STAT

  • Two new packages of checks: CERT and SECURITY.

  • The MISRA C:2012 package has been updated with about 90 new checks, of which some are enabled by default.

  • The analysis engine has been improved to increase the analysis precision for both existing and added coding rules. This can have the effect that the number of issued messages for a file or project can differ compared to previous versions of C-STAT, even if the enabled checks are exactly the same.

  • There is a new option to enable or disable the false-positives elimination phase of the analysis that is performed on each source file. (--fpe when using icstat.exe, or Enable false-positive analysis when using C-STAT in the IAR Embedded Workbench IDE.)

  • There is a new option (--exclude path) to exclude files from analysis.

  • C-STAT message suppression can now be controlled by directives placed in comments in the source files. See Descriptions of compiler extensions for C-STAT in the C-STAT Static Analysis Guide.

  • C-STAT settings in an old IAR Embedded Workbench IDE or Eclipse project will be updated. Some checks will be renamed (they retain their enabled or disabled settings), some checks are removed, and many new checks are added (see above).

  • Importing settings for C-STAT checks from a file will use the same logic as used when updating the project settings, if the settings file is created with an old version of C-STAT.

V2.20.3 - 2017-01-31

• [EW26359] Extracting a byte from a 32-bit value can sometimes corrupt local variables or data objects.

• [EW26050] Certain 32-bit operations, when implemented with library calls, do not preserve the volatileness of memory operands.

V2.20.1 - 2015-11-27

• Improved code generation and optimization
  The compiler generates smaller and faster code for certain source program constructions.

V2.10.4 - 2015-03-31

Program corrections

• [EW25222] The compiler emits a spurious error when a non-constant is used to supply the value of a bit-field member in aggregate initialization of a structure with automatic storage duration.

V2.10.3 - 2015-02-18

Program corrections

• [EW25205] Initalization of local structs or arrays with size in bytes >= 256 could destroy the value of other local variables. Assignment and parameter passing of large whole arrays or structs could also be affected by the same problem.

• [EW25206] Subtracting a 32-bit value from a constant could destroy the value of another local variable.

• [EW25207] Shifting a signed char right a constant amount >= 8 could give the wrong result.

• [EW25208] Signed bitfields in long types with a witdh of 8 or 24 bytes could yield the wrong value when read, and lead to decreased performance.

• [EW25211] The compiler gives an error if an __eeprom variable is first declared, then defined later in the same compilation unit.

• [EW25219] Internal Error occurs in the compiler when declaring an array on the stack which is larger than 32 kB.

V2.10.1 - 2014-11-20

New features

• You can choose between the default versions and smaller versions of the mathematical functions cos, sin, tan, log, log10, pow, and exp.

• Multithread supporting libraries can be built. See the C/C++ Development Guide or the online help system.

V1.42.1 - 2014-01-23

New features

• Support for static and global initialized __eeprom variables has been added.

• Absolute located variables no longer have to be declared no_init.

Program corrections

• [EW24382] In rare cases at high optimization levels, an assignment to an element of a local array can be incorrectly optimized away.

• [EW24120],[EW24436] Absolute located constants (also placed with #pragma location) causes an internal error.

V1.41.1 - 2013-07-05

• None.

V1.40.1 - 2013-03-05

New features

• New intrinsic functions
  Intrinsic functions that generate bit handle instructions from the compiler have been added. These functions are defined in intrinsics.h:
  __BCPL(a,b),
  __BRES(a,b), and
  __BSET(a,b).
  Assembler instructions with corresponding names are generated. These instructions manipulate the specified bit number (specified in b) in the byte at the address pointed out by a.
  Example:
  static unsigned char str[] = "sTM8";
__BCPL((unsigned char __near *)str,5); // "sTM8" -> "STM8"

Program corrections

• [EW22912] On optimization level High __ramfunc functions could become inlined in ROM-functions.

V1.31.2 - 2013-01-24

Program corrections

• [EW23702] Signed long comparison with zero sometimes used the wrong jump instructions.

V1.31.1 - 2012-10-04

Program corrections

• [EW23102] The linker configuration files for the STM8S20x devices had incorrect RAM region setup. This is now corrected.

• [EW23355] An error in the register allocation could generate an Internal Error: [`anonymous-namespace'::Base::Validate]: Malformed instruction. This is now corrected.

V1.30.2 - 2011-12-21

Program corrections

• [EW22619] The linker configuration files for the STM8S903 devices had incorrect RAM region setup. This is now corrected.

• [EW22772] Interrupt vectors for the STM8L151x8, STM8L152x8 and STM8L162x8 was defined incorrect in the configuration files. This is now corrected.

V1.30.1 - 2011-04-05

Program corrections

• [EW22193] Some register offsets in the Common Information Entry of interrupt handlers were wrong. This is now corrected.

V1.20.1 - 2010-11-03

New features

• EC++ and EEC++ support
  The compiler now has support for Embedded C++ and Extended Embedded C++.

• New extended keyword __ramfunc
  The __ramfunc keyword makes a function execute in RAM. If a function declared __ramfunc tries to access ROM, the compiler will issue a warning.
  Functions declared __ramfunc are by default stored in the section named *_func.textrw.
  
  Example: __ramfunc int FlashPage(char * data, char * page);

Program corrections

• [EW21775] #pragma vector=31 is added to the library files.

• [EW21865] Using non-initialized variables in arrays with struct could generate an internal error. This is now corrected.

• [EW21895] Declaring local arrays as volatile generated an internal error. This has been corrected.

• [EW21928] Declaring local variables as __far generated an internal error. This has been corrected.

• [EW21941] __section_begin on overlays sometimes returns 0 despite the actual start address of the section. This is now corrected.

V1.10.1 - 2010-05-05

Program corrections

• New ILINK configuration files with corrected placement and initializations of .tiny.rodata sections.

V1.10.0 - 2010-04-16

• First official release