Mixed programming of basic language and assembly language --- electronic watch

This is a program from a foreign website, which is programmed in a mixed language of basic and assembly language on the bascom avr platform. I downloaded it and made some modifications to it:
I removed the lcd16x4 and used the popular oled screen emulation instead.
I added Chinese setting prompts.
Note: The source program is written using Bascom-Avr-1.11.9.1. In the new version of Bascom-Avr, you need to add "!" before the assembly instructions in the non-assembly block.



$regfile = "m8def.dat"
$framesize = 32
$swstack = 32
$hwstack = 32
$crystal = 8000000

Config Portb.1 = Output 'A pin is configured as LED output

'******** LCD ******************************************************
''Set the pins of the LCD module according to your own connection if necessary
' Config Lcdpin = Pin , Db4 = Portc.2 , Db5 = Portc.3 , Db6 = Portc.4 , Db7 = Portc.5 , E = Portc.1 , Rs = Portc.0
'Config Lcdmode = Port
'Config Lcdbus = 4 '4 bit mode
' Config Lcd = 20 * 4
' Initlcd
'Cursor Off
Config Scl = Portc.5 ' Use I2C pins Scl = Portc.5, Sda = Portc.4
Config Sda = Portc.4
Config Twi = 400000 ' I2c speed

I2cinit
$lib "i2c_twi.lbx" ' Do not use software to simulate I2c, but use twi
$lib "glcdSSD1306-I2C.lib" ' Replace the default library with the glcdSSD1306-I2C library to be added to the bascom avr library

#if _build < 20784
Dim ___lcdrow As Byte , ___lcdcol As Byte ' Compile with the old version variable format
#endif

Config Graphlcd = Custom , Cols = 128 , Rows = 64 , Lcdname = "SSD1306" 'Configure the graphics display


'********* ISR Timer 2 ******************************************************
Config Clock = User 'Configure the timer for the Time$ and Date$ variables.

' You can debounce at 128Hz (max delay 4/128 = 0.031s)
Config Timer2 = Timer , Async = On , Prescale = 1 ' Prescaler 8->16Hz or 1->128Hz
On Ovf2 _isr_t2ovf Nosave
Enable Ovf2

Enable Interrupts

Config Date = ymd , Separator = - ' Configure date format Europe: dmy USA: mdy Asia: ymd
_sec = 00 : _min = 15 : _hour = 14 : _day = 21 : _month = 08 : _year = 20

Dim Flagrtc_changed As Bit
Dim Tick_128hz As Byte

'******** Enter Key and Debounce************************************************
' Assign buttons to pins - they must all be connected to the same port!
Const Key_plus = &B0000_1000 '1 = button inputConst
Key_minus = &B0001_0000
Const Key_enter = &B0010_0000

Const Pinb_mask = Key_plus + Key_minus + Key_enter 'Mask to filter inputConst
Pinb_mask_compl = &HFF - Pinb_mask 'Pinb_mask compliment

'This is a button on PortB
Ddrb = Ddrb And Pinb_mask_compl 'DDRB:0=INPUT 1=OUTPUT
Portb = Portb Or Pinb_mask '1 = Activate internal pull-up resistor for input
Key_port Alias ​​Pinb

Dim Key_state As Byte '0/1 Inverted state of the button (1 = pressed)
Dim Key_press As Byte 'Trigger key press
Dim Key_rep As Byte 'Auto repeat counter
Dim Key_ct0 As Byte , Key_ct1 As Byte '2 bit counter for debounce

Const Key_repeat_start = 127 'Number -1 of timer ISR until auto repeat starts (approx. 500-1000ms)
Const Key_repeat_next = 15 'Number -1 of timer ISR for auto repeat repeat rate (approx. 125ms)

'Debounce initial value
Key_ct0 = 255 'Intercept routine to start from key press
Key_ct1 = 255
'Key_rep = Key_repeat_start 'Paranoia

'************ General *****************************************************
Dim I As Byte , J As Byte , K As Byte , L As Byte
Dim q As Byte
Dim Setdatetime_index As Byte
Setdatetime_index = 2 'The first index of the date array is 1, 2 = _min

Dim Date_array(6) As Byte At _sec Overlay 'The array of seconds/minutes/hours/days/months/years specifies the overlay variable in memory.

'********* Main loop***************************************************
Do

' Home 'Cursor origin
' Lcd Date$ ; " " ; Time$ 'Display date and time
' Locate 2 , 1
' Lcd "Set: " ; Lookupstr(setdatetime_index , Data_dateset) 'var = LOOKUPSTR (index, label) returns a string from the table
Setfont font8x8
Lcdat 2, 16 , Date$
Setfont font12x16
Lcdat 4, 16 ,Time$
Setfont font8x8
'Lcdat 7, 16 , "Set: " ; Lookupstr(setdatetime_index , Data_dateset) 'LOOKUPSTR (index, label) returns a string from the table
'In order to save power, a 128Hz loop was written in ASM:
Setfont font12x16
q=Lookup(setdatetime_index , Data_set)
Lcdat 7, 16 ,chr(134);chr(135); ": " ; chr(q)

   Flagrtc_changed = 0
   Enable Interrupts 'Paranoia
   'Do power save cycle until ((Flagrtc_changed = 1) or (Key_press > 0))

Main_1:

Config Powermode = Powersave 'Configure power mode = power save mode If Timer/Counter 2 is enabled, it will keep running during sleep
                                                                    'Power save mode only applies to 8535, Mega8, Mega163.
! lds r16,{Key_press} 'Did the button get pressed?
  ! TST r16
  ! BRNE main_2
  ! lds r16,{flagRTC_Changed} 'Another second?
! sbrS r16,bit.flagRTC_Changed
! RJMP Main_1

Main_2:

If Key_press > 0 Then Gosub Setdatetime_input

Loop


'---------------------------------------------------------------
'Subroutine: Setdatetime_input Set datetime input

'Call from: main

'Purpose: Set date and clock

'Parameters: Key input
'---------------------------------------------------------------
Setdatetime_input:

Disable Interrupts                                         '禁用中断
    I = Key_press                                           '读取键
    Key_press = 0

    L = Lookup(setdatetime_index , Date_max)
    If Setdatetime_index = 4 Then
       L = Lookup(_month , Date_month)
       K = _year And 3
       If _month = 2 Then If K = 0 Then Incr L
    End If
    K = Lookup(setdatetime_index , Date_min)

    J = Date_array(setdatetime_index)
    If I = Key_plus Then
        If J < L Then Incr J Else J = K
    End If
    If I = Key_minus Then
        If J > K Then Decr J Else J = L
    End If
    Date_array(setdatetime_index) = J

Enable Interrupts                                          '启用中断

    If I = Key_enter Then
        If Setdatetime_index < 6 Then Incr Setdatetime_index Else Setdatetime_index = 1
    End If

Return


'********ISR计时器2***************************************************

'---------------------------------------------------------------

'子程序：'u isr_t2ovf

'呼叫来源：定时器2（128Hz）

'目的：RTC，去抖动

'结果：RTC:_秒、_min、u小时、u天、u月、u年
'          '反跳：请参见下文
'---------------------------------------------------------------
$external _soft_clock
Const _sectic = 0                                          'CONFIG CLOCK = USER，GOSUB <> SECTIC的编译器语句

_isr_t2ovf:
$asm
        push    r16
        in      r16,sreg
        push    r16                                        ' 将R16和SREG保存在堆栈中

' 防抖键
        push    r17                                         '现在保存所有使用的寄存器
        push    r18
        PUSH    r19
       Call Debounce_port
        POP     r19                                        '恢复寄存器
        pop     r18
        pop     r17

        lds     r16,{tick_128hz}                            '每1/128秒增加一次tick_128
        inc     r16
        sts     {tick_128hz},r16
        andi    r16,128-1                                   '如果_tick128不是128的倍数
        brne    _T2OVF_END                                  '   set_digit退出isr，否则已过去一秒钟

'  该位变量将每隔一秒钟设置一次
        lds     r16,{flagRTC_Changed}                       '位变量
        sbr     r16,2^bit.flagRTC_Changed
        sts     {flagRTC_Changed},r16                       '注意标志是重置标志的主要代码责任

'  转至内部Bascom ISR例行程序：软时钟
        pop r16 'Get contents of SREG
        !out sreg,r16 'Restore sreg
        pop r16
        JMP _SOFT_CLOCK 'Original RETI

_t2ovf_end:
        pop r16 'Get contents of SREG
        !out sreg,r16 'Restore SREG
        pop r16

$end Asm
Return 'Leave isr with RETI

'********Debounce******************************************************
'------------------------------------------------- --------------
'Subroutine: Debounce_port
''Detects up to 8 keys simultaneously, with debounce and auto-repeat capabilities
'Each key is scanned 3 times to change state
'Registers used: R16, R17, R18, R19
'Variables: Key_state state for key 0/1
'Key_rep repeat counter for auto-repeat
'Key_ct0 / Key_ct1 2-bit counter for debounce
'Result: Key_press: pin bit goes to 1 when key press is detected
'After reading it out, reset the state of Key_press in Main!
'Thanks to Peter Dannegger
'---------------------------------------------------------------
Debounce_port: 'About 108 bytes
  $asm
    in R18, key_port
    com R18 'Pin active low
    ANDI R18, Pinb_mask 'Filter pins with Pinb_mask
    LDS R19, {Key_state}
    eor R18, R19 'Detect level change at pin input

    LDS R16, {Key_ct0} '8 channel 2-bit counter
    LDS R17, {Key_ct1}
    and R16, R18 'Reset 2-bit counter in R17: R16
    and R17, R18
    com R16 'Decrement R17: R16
    eor R17, R16
    STS {Key_ct0} , R16 'Save counter
    STS {Key_ct1} , R17

    and R18, R16 'IF counter=&B11 Set digital input blanking
    and R18, R17
    eor R19, R18 '0<->1 switch state
    STS {Key_state} , R19

    LDS R16, {key_press}
    and R18, R19
    or R16, R18 'Detected "0->1 key press

    LDS R17, {Key_rep}
    tst R19 'Key_state: Is any key pressed?
    breq Key_isr_rep
    dec R17
    brpl Key_isr_finish 'IF Key_rep <0 set_digit wait time expires
    mov R16, R19 'Auto repeat key_press = key_state
    ldi R17,key_repeat_next 'Set up auto-reply repeat timer
    rjmp Key_isr_finish

Key_isr_rep:
    ldi R17, key_repeat_start 'Reset auto reply start

timerKey_isr_finish:
    STS {Key_rep} , R17 'Save auto reply timerSTS
    {key_press} , R16 'Save debounce key
  $end Asm
Return


'******** RTC *******************************************************
'The following empty routine if you want to use
'time/date bascom functions. , 31 , 28 , 31 , 30 , 31 , 30 , 31 , 30 ,     31 ,     30 , 31 '12 month end mark
Data_dateset : Data " " ,     " Sec " , "Min " , "Hour" , "Day " , "Month " , "Year" minimum mark Date_max: Data 0 , 59 , 59 , 23 , 31 , 12 , 99 ''Second " , "Min " , "Hour" , "Day " , "Month " , "Year" maximum mark Date_month: Data 0 , 31 , 28 , 31 , 30 , 31 , 30 , 31 , 30 , 31 , 30 , 31 '12 month end mark Data_dateset: Data " " , "Sec " , "Min " , "Hour" , "Day " , "Mon " , "Year" 'Seconds", "Minutes", "Hours", "Day", "Month", "Year" Data_set: Data 0 , 128, 129 , 130 , 131 , 132, 133 'Seconds", "Minutes", "Hours", "Day", "Month", "Year" $include "../font8x8.font" $include "../font12x16.font"