void tn_start_system(void)
{
    ...
    tn_task_create((TN_TCB*)&tn_timer_task,        //-- task TCB
                  tn_timer_task_func,             //-- task function
                  0,                              //-- task priority
                  &(tn_timer_task_stack           //-- task stack first addr in memory
                      [TN_TIMER_STACK_SIZE-1]),
                  TN_TIMER_STACK_SIZE,            //-- task stack size (in int,not bytes)
                  NULL,                           //-- task function parameter
                  TN_TASK_TIMER);                 //-- Creation option

   //--- Idle task

    tn_task_create((TN_TCB*)&tn_idle_task,         //-- task TCB
                  tn_idle_task_func,              //-- task function
                  TN_NUM_PRIORITY-1,              //-- task priority
                  &(tn_idle_task_stack            //-- task stack first addr in memory
                      [TN_IDLE_STACK_SIZE-1]),
                  TN_IDLE_STACK_SIZE,             //-- task stack size (in int,not bytes)
                  NULL,                           //-- task function parameter
                  TN_TASK_IDLE);                  //-- Creation option    
}