clock.jal

VAR BYTE*8 clock_absolute = 0 -- range 0 - 2**64
VAR BYTE*2 clock_millisecond = 0  -- range 0 - 999
VAR BYTE clock_second = 0  -- range 0 - 59 
VAR BYTE clock_minute = 0  -- range 0 - 59
VAR BYTE clock_hour = 12  -- range 0 - 23
VAR BYTE clock_weekday = 3  -- range 0 - 6 sun - sat
VAR BYTE*2 clock_doy = 73 -- range 0 - 366 
VAR BYTE*3 clock_mjd = 56000  
VAR BYTE*2 clock_year = 2012 -- range 1800 - 2**16

-- (clock defaults to 2012-03-16 Tue, aka MJD 56000)



 


function is_leap_year(byte*2 in year) return bit is
    if (year & 0b11) == 0b00 then -- divisible by 4.
        if (year % 100) != 0 then -- unless divisible by 100
            return true
        else
            if (year % 400) == 0 then -- but if divisible by 400
                return true
            end if
        end if
    end if
    return false
end function


const byte*2 leapyears[] = {
    2012,    2016,    2020,    2024,
    2028,    2032,    2036,    2040,
    2044,    2048,    2052,    2056,
    2060,    2064,    2068,    2072,
    2076,    2080,    2084,    2088,
    2092,    2096,    2104,    2108
    };

function clock_leap_year(byte*2 in year) return bit is
    var byte idx
    for count(leapyears) using idx loop
        if year == leapyears[idx] then
            return true
        end if
    end loop
    return false
end function



function clock_year_len(byte*2 in year) return byte*2 is
    if clock_leap_year(year) then
        return 366
    else
        return 365
    end if
end function




PROCEDURE timer0_isr_wedge() IS
    pragma inline
    -- This is called in the Timer0 ISR, yielding 1ms precision
    clock_millisecond = clock_millisecond + 1
    clock_absolute = clock_absolute + 1
    IF clock_millisecond > 999 THEN
        clock_millisecond = 0
        clock_second = clock_second + 1
        IF clock_second > 59 THEN
            clock_second = 0
            clock_minute = clock_minute + 1
            IF clock_minute > 59 THEN
                clock_minute = 0
                clock_hour = clock_hour + 1
                IF clock_hour > 23 THEN
                    clock_hour = 0
                    clock_mjd = clock_mjd + 1
                    clock_weekday = clock_weekday + 1
                    IF clock_weekday > 6 THEN
                        clock_weekday = 0
                    END IF
                    clock_doy = clock_doy + 1
                    if clock_doy > (clock_year_len(clock_year)) then
                        clock_doy = 1
                        clock_year = clock_year + 1
                    end if
                END IF
            END IF
        END IF
    END IF
END PROCEDURE


procedure print_time is
    -- 2012-000 Wed 00:00:00.000
    --print_string("MJD")
    --format_dword_dec(usb_serial_data, clock_mjd, 6, 0)
    --usb_serial_data = " "
    format_word_dec(usb_serial_data, clock_year, 4, 0)
    usb_serial_data = "-"
    format_word_dec(usb_serial_data, clock_doy, 3, 0)
    usb_serial_data = " "
    format_time_hms(usb_serial_data, clock_hour, clock_minute, clock_second)
    usb_serial_data = "."
    format_word_dec(usb_serial_data, clock_millisecond, 3, 0)
end procedure