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Long Hex ASCII string to decimal ASCII

Using the C51 tools, I am trying to convert a long Hex number, entered as an ASCII string, to its decimal equivalent.
For example:
the string could be:
"ABCDEF1234565"
And I would need to convert to the string:
"188900967593046"

The problem I have found is that since there does not seem to be a true 'double' variable type, I cannot do a direct conversion of the number. Which would consist of converting the ASCII hex to a variable, and then printing it out as decimal.

I have tried several methods, but cannot get past needing variable storage larger than 32bits.

Any suggestions on how to achieve this would be greatly appreciated...

Thanks!

David Marten

Parents

0 Mik Kleshov over 23 years ago

On Nov. 11, 2001, I sent in a C51 V6.20 bug report via e-mail to support.us@keil.com. I never received a response, so assumed Keil's policy was to silently introduce the bug fix in a subsequent update. After downloading V6.21, I see that the bug is still present. Now I'm wondering whether my e-mailed bug report was ever acted upon, so I'm going to try the forum as the means to report the bug. 
 
I have a section of code with pointer incrementation that compiles and executes correctly when the pointer is defined as a generic pointer or as an xdata pointer, or when the optimization setting is reduced from the default OT(8,SPEED) to OT(7,SPEED). However, when the pointer is defined as a data or idata pointer, the compiler does not emit code to increment the pointer with default optimization. 
 
I have provided example code demonstrating the problem. The specific statement is line 50 below.

unsigned char idata u64[8] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
unsigned char idata s[21];

void U64ToStr( char idata *s, unsigned char idata *binP, unsigned char n )
{
    unsigned char        bcd;
    unsigned char idata *bcdP;
    unsigned char        bitMsk = 0x80;
    unsigned char        carry;
    unsigned char        i;

    /*  Zero the target buffer (NUL-terminating the string).
     */
    for (bcdP = s, i = n + 1; i != 0; *bcdP++ = 0, i--)
        ;

    /*  Convert 64 bits of binary to unpacked BCD.  For each bit, starting
     *  with the MSBit, BCD = (BCD * 2) + bit.
     */
    for (i = 64; i != 0; i--)
    {
        carry = (*binP & bitMsk) ? 1 : 0;

        for (bcdP = s + n; bcdP != s; /* Iter in body */)
        {
            bcd  = *--bcdP * 2;
            bcd += carry;

            if (bcd < 10)
                carry = 0;
            else
            {
                carry = 1;
                bcd  -= 10;
            }

            *bcdP = bcd;
        }

        if ((bitMsk >>= 1) == 0)
        {
            bitMsk = 0x80;
            binP++;
        }
    }

    /*  ASCII'fy BCD.
     */
    for (i = n; i != 0; i--)
        *bcdP++ += '0'; /* <-- C51 BUG: bcdP doesn't increment for (i)data */
}

void main( void )
{
    for (;;)
        U64ToStr( s, u64, 6 );
}

--Dan Henry

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0 Mik Kleshov over 23 years ago

unsigned char idata u64[8] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
unsigned char idata s[21];

void U64ToStr( char idata *s, unsigned char idata *binP, unsigned char n )
{
    unsigned char        bcd;
    unsigned char idata *bcdP;
    unsigned char        bitMsk = 0x80;
    unsigned char        carry;
    unsigned char        i;

    /*  Zero the target buffer (NUL-terminating the string).
     */
    for (bcdP = s, i = n + 1; i != 0; *bcdP++ = 0, i--)
        ;

    /*  Convert 64 bits of binary to unpacked BCD.  For each bit, starting
     *  with the MSBit, BCD = (BCD * 2) + bit.
     */
    for (i = 64; i != 0; i--)
    {
        carry = (*binP & bitMsk) ? 1 : 0;

        for (bcdP = s + n; bcdP != s; /* Iter in body */)
        {
            bcd  = *--bcdP * 2;
            bcd += carry;

            if (bcd < 10)
                carry = 0;
            else
            {
                carry = 1;
                bcd  -= 10;
            }

            *bcdP = bcd;
        }

        if ((bitMsk >>= 1) == 0)
        {
            bitMsk = 0x80;
            binP++;
        }
    }

    /*  ASCII'fy BCD.
     */
    for (i = n; i != 0; i--)
        *bcdP++ += '0'; /* <-- C51 BUG: bcdP doesn't increment for (i)data */
}

void main( void )
{
    for (;;)
        U64ToStr( s, u64, 6 );
}

--Dan Henry

Children

0 Mik Kleshov over 23 years ago in reply to Mik Kleshov

Obviously, the forum messed up my last message. Here is what I ment.
Seems like you can't avoid using 64-bit long numbers, as Graham said. To see some ways of converting binary into decimal, follow the link:
http://www.public.asu.edu/~vidar/bcdchange.html

Regards,
Mike
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