while (DEF_TRUE) {
        msg = (CPU_INT08U *)(OSMboxPend(AppUserIFMbox, OS_TICKS_PER_SEC / 3, &err));
        if (err == OS_NO_ERR) {
            nstate = (CPU_INT32U)msg;
        }

        if (nstate != pstate) {
            DispClrScr();
            pstate  = nstate;
        }

        switch (nstate) {
            case 2:
                 AppDispScr_VersionTickRate();
                 break;

            case 3:
                 AppDispScr_CPU();
                 break;

            case 4:
                 AppDispScr_CtxSw();
                 break;


            case 1:
            default:
                AppDispScr_SignOn();
                break;
        }
    }
}
#endif

/*
*********************************************************************************************************
*                                    KEYBOARD RESPONSE TASK
*
* Description : This task monitors the state of the push buttons and passes messages to AppTaskUserIF()
*
* Arguments   : p_arg   is the argument passed to 'AppStartKbd()' by 'OSTaskCreate()'.
*
* Returns     : none
*********************************************************************************************************
*/

static  void  AppTaskKbd (void *p_arg)
{
    CPU_BOOLEAN  b1_prev;
    CPU_BOOLEAN  b1;
    CPU_BOOLEAN  b2_prev;
    CPU_BOOLEAN  b2;
    CPU_INT08U   key;


    (void)p_arg;

    b1_prev = DEF_FALSE;
    b2_prev = DEF_FALSE;
    key     = 1;

    while (DEF_TRUE) {
        b1 = PB_GetStatus(1);
        b2 = PB_GetStatus(2);

        if (b1 == DEF_TRUE && b1_prev == DEF_FALSE) {
            if (key == 4) {
                key = 1;
            } else {
                key++;
            }

            OSMboxPost(AppUserIFMbox, (void *)key);
        }

        if (b2 == DEF_TRUE && b2_prev == DEF_FALSE) {
            LCD_LightToggle();
        }

        b1_prev = b1;
        b2_prev = b2;

        OSTimeDlyHMSM(0, 0, 0, 20);
    }
}


/*
*********************************************************************************************************
*                                            DISPLAY SCREENS
*
* Descrition:  These functions each display one of the screens used in the demonstration.
*
* Arguments :  none
*
* Returns   :  none
*********************************************************************************************************
*/

#if (uC_LCD_MODULE > 0)
static  void  AppDispScr_SignOn (void)
{
    OS_StrCopy(AppLCDLine1, "Micrium uC/OS-II");
    OS_StrCopy(AppLCDLine2, "STMicro    STM32");

    DispStr(0, 0, AppLCDLine1);
    DispStr(1, 0, AppLCDLine2);
}

static  void  AppDispScr_VersionTickRate (void)
{
    CPU_INT32U      value;


    OS_StrCopy(AppLCDLine1, "uC/OS-II:  Vx.yy");
    value           = (CPU_INT32U)OSVersion();
    AppLCDLine1[12] =  value / 100       + '0';
    AppLCDLine1[14] = (value % 100) / 10 + '0';
    AppLCDLine1[15] = (value %  10)      + '0';

    OS_StrCopy(AppLCDLine2, "TickRate:   xxxx");
    value = (CPU_INT32U)OS_TICKS_PER_SEC;
    AppFormatDec(&AppLCDLine2[12], value, 4);

    DispStr(0, 0, AppLCDLine1);
    DispStr(1, 0, AppLCDLine2);
}

static  void  AppDispScr_CPU (void)
{
    CPU_INT32U      value;


    OS_StrCopy(AppLCDLine1, "CPU Usage:xx %  ");
    value           = (CPU_INT32U)OSCPUUsage;
    AppLCDLine1[10] = (value / 10) + '0';
    AppLCDLine1[11] = (value % 10) + '0';

    OS_StrCopy(AppLCDLine2, "CPU Speed:xx MHz");
    value           = (CPU_INT32U)BSP_CPU_ClkFreq() / 1000000L;
    AppLCDLine2[10] = (value / 10) + '0';
    AppLCDLine2[11] = (value % 10) + '0';

    DispStr(0, 0, AppLCDLine1);
    DispStr(1, 0, AppLCDLine2);
}

static  void  AppDispScr_CtxSw (void)
{
    CPU_INT32U      value;


    OS_StrCopy(AppLCDLine1, "#Ticks: xxxxxxxx");
    value = (CPU_INT32U)OSTime;
    AppFormatDec(AppLCDLine1 + 8, value, 8);

    OS_StrCopy(AppLCDLine2, "#CtxSw: xxxxxxxx");
    value = (CPU_INT32U)OSCtxSwCtr;
    AppFormatDec(AppLCDLine2 + 8, value, 8);

    DispStr(0, 0, AppLCDLine1);
    DispStr(1, 0, AppLCDLine2);
}
#endif



/*
*********************************************************************************************************
*                                         STRING OUTPUT TASK
*
* Description : This task constantly output a string via the uC/Probe general communication module.
*
* Arguments   : p_arg   is the argument passed to 'AppTaskProbeStr()' by 'OSTaskCreate()'.
*
* Returns     : none
*********************************************************************************************************
*/

#if (uC_PROBE_COM_MODULE   > 0) && \
    (PROBE_COM_SUPPORT_STR > 0)
static  void  AppTaskProbeStr (void *p_arg)
{
            CPU_INT32U   i;
    static  CPU_CHAR     buffer[64];


    i   = 0;

    while (DEF_TRUE) {
        Str_Copy(buffer, "String Tx #xxxxx\n");
        AppFormatDec(&buffer[11], i, 5);
        i++;
        ProbeCom_TxStr(buffer, 100);
        OSTimeDlyHMSM(0, 0, 1, 0);
    }
}
#endif


/*
*********************************************************************************************************
*                                         uC/Probe Callback
*
* Description : This task is called by the uC/Probe uC/OS-II plug-in after updating task information.
*
* Arguments   : none.
*
* Returns     : none
*********************************************************************************************************
*/

#if (uC_PROBE_OS_PLUGIN > 0)
static  void  AppProbeCallback (void)
{
#if (uC_PROBE_COM_MODULE   > 0) && \
    (PROBE_COM_STAT_EN     > 0)
    CPU_INT32U  ctr_curr;
    CPU_INT32U  rx_curr;
    CPU_INT32U  tx_curr;
    CPU_INT32U  rxpkt_curr;
    CPU_INT32U  txpkt_curr;
    CPU_INT32U  sym_curr;
    CPU_INT32U  symbyte_curr;
#endif


    Probe_Counts++;

    Probe_B1       = PB_GetStatus(1);
    Probe_B2       = PB_GetStatus(2);
    Probe_B3       = PB_GetStatus(3);
    Probe_B_WakeUp = PB_GetStatus(4);

    Probe_ADC      = (ADC_GetStatus(1) * 100) / 0x1000;

#if (uC_PROBE_COM_MODULE   > 0) && \
    (PROBE_COM_STAT_EN     > 0)
    ctr_curr     = OSTime;
    rxpkt_curr   = ProbeRS232_RxPktCtr;
    txpkt_curr   = ProbeRS232_TxPktCtr;
    rx_curr      = ProbeRS232_RxCtr;
    tx_curr      = ProbeRS232_TxCtr;
    sym_curr     = ProbeCom_TxSymCtr;
    symbyte_curr = ProbeCom_TxSymByteCtr;

    if ((ctr_curr - Probe_ComCtrLast) >= OS_TICKS_PER_SEC) {

        Probe_RS232RxSpd      = ((CPU_FP32)(rx_curr      - Probe_RS232RxLast)      / (ctr_curr - Probe_ComCtrLast)) * OS_TICKS_PER_SEC;
        Probe_RS232TxSpd      = ((CPU_FP32)(tx_curr      - Probe_RS232TxLast)      / (ctr_curr - Probe_ComCtrLast)) * OS_TICKS_PER_SEC;
        Probe_ComRxPktSpd     = ((CPU_FP32)(rxpkt_curr   - Probe_ComRxPktLast)     / (ctr_curr - Probe_ComCtrLast)) * OS_TICKS_PER_SEC;
        Probe_ComTxPktSpd     = ((CPU_FP32)(txpkt_curr   - Probe_ComTxPktLast)     / (ctr_curr - Probe_ComCtrLast)) * OS_TICKS_PER_SEC;
        Probe_ComTxSymSpd     = ((CPU_FP32)(sym_curr     - Probe_ComTxSymLast)     / (ctr_curr - Probe_ComCtrLast)) * OS_TICKS_PER_SEC;
        Probe_ComTxSymByteSpd = ((CPU_FP32)(symbyte_curr - Probe_ComTxSymByteLast) / (ctr_curr - Probe_ComCtrLast)) * OS_TICKS_PER_SEC;

        Probe_ComCtrLast       = ctr_curr;
        Probe_RS232RxLast      = rx_curr;
        Probe_RS232TxLast      = tx_curr;
        Probe_ComRxPktLast     = rxpkt_curr;
        Probe_ComTxPktLast     = txpkt_curr;
        Probe_ComTxSymLast     = sym_curr;
        Probe_ComTxSymByteLast = symbyte_curr;
    }
#endif
}
#endif


/*
*********************************************************************************************************
*                                      FORMAT A DECIMAL VALUE
*
* Description: This function converts a decimal value to ASCII (with leading zeros)
*
* Arguments  : s       is a pointer to the destination ASCII string
*              value   is the value to convert (assumes an unsigned value)
*              digits  is the desired number of digits
*
* Returns    : none
*********************************************************************************************************
*/

static  void  AppFormatDec (CPU_INT08U *s, CPU_INT32U value, CPU_INT08U digits)
{
    CPU_INT08U      i;
    CPU_INT32U      mult;


    mult = 1;
    for (i = 0; i < (digits - 1); i++) {
        mult *= 10;
    }
    while (mult > 0) {
        *s++   = value / mult + '0';
        value %= mult;
        mult  /= 10;
    }
}


/*
*********************************************************************************************************
*                                   APPLICATION-DEFINED HOOKS
*
* Description: These functions are called by the hooks in os_cpu_c.c.
*
* Returns    : none
*********************************************************************************************************
*/

#if (OS_APP_HOOKS_EN > 0)
void  App_TaskCreateHook (OS_TCB *ptcb)
{
#if (uC_PROBE_OS_PLUGIN > 0) && (OS_PROBE_HOOKS_EN > 0)
    OSProbe_TaskCreateHook(ptcb);
#endif
}


void  App_TaskDelHook (OS_TCB *ptcb)
{
    (void)ptcb;
}


#if OS_VERSION >= 251
void  App_TaskIdleHook (void)
{
}
#endif


void  App_TaskStatHook (void)
{
}


#if OS_TASK_SW_HOOK_EN > 0
void  App_TaskSwHook (void)
{
#if (uC_PROBE_OS_PLUGIN > 0) && (OS_PROBE_HOOKS_EN > 0)
    OSProbe_TaskSwHook();
#endif
}
#endif


#if OS_VERSION >= 204
void  App_TCBInitHook (OS_TCB *ptcb)
{
    (void)ptcb;
}
#endif


#if OS_TIME_TICK_HOOK_EN > 0
void  App_TimeTickHook (void)
{
#if (uC_PROBE_OS_PLUGIN > 0) && (OS_PROBE_HOOKS_EN > 0)
    OSProbe_TickHook();
#endif
}
#endif
#endif