Class B software package

AN3181

14/31

Doc ID 17286 Rev 2

A new Class B variable must be declared as a complementary pair of two variables

allocated at different segments by definition placed into proper part of the

stm32fxxx_STLclassBvar.h header file.

The following syntax is used for the compilers:

Cosmic

EXTERN @near u16 MyClassBVariable;

....

EXTERN @near u16 MyClassBVariableInv;

IAR

EXTERN __near u16 MyClassBVariable @ "CLASS_B_RAM";

.....

EXTERN __near u16 MyClassBVariableInv @ "CLASS_B_RAM_REV";

Raisonance

EXTERN near u16 MyClassBVariable;

.....

EXTERN near u16 MyClassBVariableInv;

Note:

When the version of STVD tool does not support including the vector table content into the

checksum computation and the user wants to protect this part of the code, the proper linker

script file must be modified by placing the vector table as follows:

The line: “+seg .const -b 0x8000 -k” must be replaced by: “+seg .const -b 0x8000 -k -ck”.

Note:

Previously, “__ckdend__” symbol definition needed to be to included into linker script file for

some older versions of Cosmic compiler. There is no longer any need to use it.

3.2.3

Application demonstration example

A short example of user application is attached in each project main.c file with respect to

the package integration criteria (see Chapter 4: Class B solution structure). Except for

STM8L_10x, the examples were written to run on the corresponding STM8 evaluation

boards (STM8S/128-EVAL and STM8L1526-EVAL) as Class B package demonstration

firmware. They use on board LCD and LED diodes to display current versus initial master

clock frequency measurement changes. Display or LED outputs can be disabled in main.h

file. The main loop also performs initialization and calling all run mode tests at ordinary

intervals.

3.3

Package configuring and debugging

A functional part of the package may need to be changed, suspended, excluded or included.

For example the microcontroller type might need to be changed or there could be a

non-volatile memory space limitation. Modifications are also required to debug the user

application. This section describes how the ST solution can be configured, modified and

debugged.