Mark Rages <markrages@gmail.com> wrote:
> On 4/30/05, Dennis Crawley <proyectosenpic@yahoo.com.ar> wrote:
>> Mark Rages <markrages@gmail.com> wrote:
>>> Yes, and I applaud you for it.
>>>
>>> Anyone *else* used AN575 arithmetic?
>>
>> Your results are OK!.
>> The problem is the Microchip format.
>> To convert to IEEE format simple do this:
>>
>> IEEE_to_PIC16/17  PIC16/17_to_IEEE
>> RLCF AARGB0,F     RLCF AARGB0,F
>> RLCF AEXP,F       RRCF AEXP,F
>> RRCF AARGB0,F     RRCF AARGB0,F
>>
>> delete de C for 16 series.
>>
>
> Thanks.
>
> I'm not sure that solves my problem though.

I do.

>
> I'll try it on a simulator when I have time and post the raw
> (unconverted) byte values.


I've already did it for you, this is the code. Do not forget all the
includes, and read carefully page 3 of AN575:


;-1.0 + -1.0 =3D -2.0
;-1.0 =3D IEEE FORMAT: BF800000
;-1.0 =3D PIC  FORMAT: 7F800000
;Expected:
;-2.0 =3D IEEE FORMAT: C0000000
;-2.0 =3D PIC  FORMAT: 80800000

SELF
;input in IEEE format

  MOVLW 0xbf
  MOVWF AEXP
  MOVLW 0x80
  MOVWF AARGB0
  MOVLW 0x00
  MOVWF AARGB1

  MOVLW 0xbf
  MOVWF BEXP
  MOVLW 0x80
  MOVWF BARGB0
  MOVLW 0x00
  MOVWF BARGB1

IEEE2MCHP:
        RLF    AARGB0,F
        RLF    AEXP,F
        RRF    AARGB0,F

        RLF    BARGB0,F ;yeah!
        RLF    BEXP,F   ;also this one
        RRF    BARGB0,F


  CALL FPA24

MCHP2IEEE:
        RLF AARGB0,F
        RRF AEXP,F
        RRF AARGB0,F

  GOTO SELF

Voil=E1!
Dennis Crawley
Argentina.

:))))$300!!!


--=20
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist