BCD Problem

[alamy]

Hi...

i'm looking to binary to decimal conversion, BCD...i search at piclist and found it.

but looking to the code, i come across 'new' code there..pls explain

this code convert 4bit to BCD 2 digits.

Input:

W is a binary number in the range 0..29

Output:

W is a BCD number in the range 0x00..0x29

; W is 0..29

    addlw    .256-.20        ; C will be set if number was >= 20
    skpnc
    addlw    .6                   ; ...adjust for 20..29
    addlw    -(.256-.20)    ; Back to original value

    addlw    .256-.10       ; C will be set if number was >= 10
    skpnc
    addlw    .6                  ; ...adjust for 10..29
    addlw    -(.256-.10)   ; Back to original value

skpnc?...what it's?

thank you in advance

 

[williB]

https://www.electro-tech-online.com/custompdfs/2004/11/33014g.pdf

page 200..

it took a lot to find this..

 

[williB]

apparently there are more than the 36 instructions we are used to..

Table B.11: 12-Bit/14-Bit Core Special Instruction Mnemonics (Continued)

 

[williB]

SKPNZ Skip on Non Zero is equivalent to --> BTFSC 3,2 -

 

[Nigel Goodwin]

apparently there are more than the 36 instructions we are used to..

They are not actually instructions, but a kind of macro command, or even just a 'define', they simply get replaced by one or two lines of assembler code as the assembler runs.

As with everything else, they are all listed in the MPASM helpfile - this should be the first place to look for anything to do with the MPASM assembler!.