Retrieving 32bit Multiply Result

[Darrel Taylor]

Yup,

Looks great to me.

Nice reduction.
<br>

[Josuetas]

I was so confused about the Multiply operation that i posted here but.... i am now just using ** and * :s sorry

[Josuetas]

Well i am really proud of this, i Hope its ok.

For anyone in need of a Division of a BigWord by some number i found this problem:

Lets think of a BigWord as considered before ^

Now you might want to Divide a value stored in tBigWord1 by some other value, in this case (EXAMPLE CODE) the value is stored in factoriva.

One could use the DIV32 function as proposed by Darrel in this or other post BUT if factoriva is too small the result CAN be higher than a word size FFFF, and the the result is no good.

For example:

4:01F5 DIV32 2 the result of DIV32 is

Result = FFFF, Remainder = 01F7 !! Wrong i guess

This code is possible just thanks to Darrel`s @ PutMulResult?D MACRO

Bigword   var word [2]
BigwordL  var BigWord(0)
BigwordH  var BigWord(1)
Bigword1  var word [2]
Bigword1L var BigWord(0)
Bigword1H var BigWord(1)

MainLoop:
    lcdout $fe,1
    tbigword1H = 4         ' My Dollars Value High Word
    tbigword1L = 501      ' My Dollars value Low Word
    cents = 24              ' My cents value

    GOSUB DIVBIGWORD
    HSEROUT [#FactorIva," ",HEX4 tBigWordH,":", HEX4 tBigWordHL,10,13]

    FactorIva= FactorIva+ 1
    IF FactorIva= 101 THEN
         END
    ENDIF    
    GOTO MainLoop

'This SUB receives  tBigWord1(Dword) a value to be divided by
'FactorIva (word), Result in tBigWord, works for any value of FactorIva
'and tBigWord1 in their limits.
DIVBigWord:  
    tBigWordH= tBigWord1H / FactorIva
    tBigWord1H = tBigWord1H // FactorIva
    @ PutMulResult?D  _tBigWord1
    tBigWordL = DIV32 FactorIva
    Remainder = R2
    RETURN

This code in the serial port os The value tBigWord1 Divided for Factors 1 to 100
Seems to work.
Factor Result
2 0002:00FA

Remember to Add the @ PutMulResult?D MACRO posted by Darrel at the begining of the Code.

[Nicmus]

Hello everyone,

I was wandering if it is possible to implement the extended 32 bit idea to something as simple as for / next loop.
How will this simple loop look like if I need to deal with more than word size index:

For index =0 to big_number
Hserout [record(index),13,10]
Pause 100
Next

Is it possible to have a big_number = 1,000,000 – 2,000,000?

Thank you for your input.

Nick

[skimask]

Is it possible to have a big_number = 1,000,000 – 2,000,000?
Nick

It's directly possible if you have the PBP 2.50a upgrade, which supports signed/32 bit LONG variables...

[mister_e]

for PIC18 only !

[skimask]

for PIC18 only !

Got my back everywhere, dontcha?