AIRCR=0x05FA0004;

#define NVIC_SYSRESETREQ            2         /*!< System Reset Request         */
#define NVIC_AIRCR_VECTKEY    (0x5FA << 16)   /*!< AIRCR Key for write access   */
...
static __INLINE void NVIC_SystemReset(void)
{
  SCB->AIRCR  = (NVIC_AIRCR_VECTKEY | (SCB->AIRCR & (0x700)) | (1<<NVIC_SYSRESETREQ)); /* Keep priority group unchanged */
  __DSB();                                                                             /* Ensure completion of memory access */
  while(1);                                                                            /* wait until reset */
}

volatile unsigned char ResetRqFlag;
int main() {
if (ResetRqFlag) {
    ResetRqFlag=0;
    NVIC_SystemReset();
}

void HardFault_Handler(void)
{
for (;;)
    GPIO->P[2].DOUTTGL=1;
}

void OS::system_timer_user_hook() {// вызывается с частотой 1кГц
    DWT_CYCCNT=0;

    if (++Divider==1000) {// 1 секунда
        Divider=0;
        TimerEvent.signal_isr();
    }
    Timers[0]=DWT_Get();
}

template<>
OS_PROCESS void TProc1::exec() {
    uint16_t reset_delay_cnt=0;
    for (;;) {
        TimerEvent.wait();
        Timers[1]=DWT_Get();
        {// Сброс
            if (++reset_delay_cnt==20) {// сброс через 20 секунд
                ResetRqFlag=0;
                SCB->AIRCR=0x05FA0004;
                while (1);
            }
        }
    }
}