STC12C2052AD MCU watchdog and its overflow time calculation formula

;This program is used to verify the watchdog and overflow time calculation formula of STC12C2052AD series microcontroller 
;Watchdog and overflow time = (12 * Pre_scale *32768)/Oscillator Frequency 

WDTCR EQU 0E1H ;Watchdog address 

WDT_TIME_LED EQU P1.5 ;Use P1.5 to control the watchdog overflow time indicator light,  
                         ;The watchdog overflow time can be represented by the length of time the indicator light is on or off 
WDT_FLAG_LED EQU P1.7 ;Use P1.7 to control the watchdog overflow reset indicator light, such as lighting, indicating a watchdog overflow reset 

Last_WDT_Time_LED_Status EQU 00H ;Bit variable, stores the last status bit of the watchdog overflow time indicator light 

;WDT reset time (Oscillator frequency = 18.432M Hz ): 
;Pre_scale_Word EQU 00111100B ;Clear, start watchdog, prescaler number = 32 0.68S 
Pre_scale_Word EQU 00111101B ;Clear, start watchdog, prescaler number = 64 1.36S 
;Pre_scale_Word EQU 00111110B ; Clear to 0, start watchdog, prescaler = 128 2.72S 
; Pre_scale_Word EQU 00111111B ; Clear to 0, start watchdog, prescaler = 256 5.44S 

    ORG 0000H 
    AJMP MAIN 

    ORG 0100H 
MAIN: 
     MOV A, WDTCR ; Check if it is watchdog reset 
    ANL A, #10000000B 
    JNZ WDT_Reset ; WDTCR.7 = 1, watchdog reset, jump to watchdog reset program 

; power-on reset, cold start, RAM unit content is random value 
    SETB Last_WDT_Time_LED_Status ; power-on reset, 
                                         ; initialize the status bit of watchdog overflow time indicator = 1 
    CLR WDT_TIME_LED ; power-on reset, light up the watchdog overflow time indicator 
     MOV WDTCR, #Pre_scale_Word ;Start watchdogWAIT1 

: 
    SJMP WAIT1 ;Execute this statement in a loop (stop), wait for watchdog overflow reset 

; watchdog reset, hot start, RAM unit content remains unchanged, the value before reset 
WDT_Reset: ; watchdog reset, hot start 
    CLR WDT_FLAG_LED ; light up the watchdog overflow reset indicator 

    JB Last_WDT_Time_LED_Status, Power_Off_WDT_TIME_LED 
    ; set the WDT_TIME_LED light according to the last status bit of the watchdog overflow time indicator,  
    ; if it was on last time, it will be off this time, if it was off last time, it will be on this time 
    CLR WDT_TIME_LED ; last time it was off, light up the watchdog overflow time indicator 
    CPL Last_WDT_Time_LED_Status ; invert the last status bit of the watchdog overflow time indicator 
WAIT2:     
    SJMP WAIT2 ; Execute this statement in a loop (stop), wait for the watchdog overflow reset 

Power_Off_WDT_TIME_LED: 
    SETB WDT_TIME_LED ; The watchdog overflow time indicator light was off this time if it was 
    on last time CPL Last_WDT_Time_LED_Status ; Invert the last status bit of the watchdog overflow time indicator light 
WAIT3:    
    SJMP WAIT3 ; Execute this statement in a loop (stop), wait for the watchdog overflow reset 

    END