Binary numbers in ASM

[slowfiddler]

This trivial test compiles with the error:

"[ASM Error]: Error[113]test.asm 1007 : symbol not previously defined (B)"

Code: Select all

Sub Init()
Asm

movlw		b'00101000'
movwf		SSPCON1
clrf		SSPCON2

End Asm
End Sub

Init()

end

It compiles fine if I replace b'00101000' with 0x28

Is there a special syntax for giving numbers in binary format in Swordfish ASM? The form above is standard for MPASM I think.

Thanks

[David Barker]

The problem is that Swordfish sees the ' (single quote) as a comment, so the line is being removed by the preprocessor. It would be fair to argue that it should not do this between asm...endasm blocks but unfortunately, the preprocessor only works on a line by line basis.

In short, I'm afraid you will need to enter the number in hex (0x)

[slowfiddler]

I feel a plugin coming on - a pre-preprocessor that converts the b'nnnnnnnn' into 0xnn. Or something.

[Jerry Messina]

I know this doesn't deal with your original question, but what's wrong with

Code: Select all

sub Init()
	SSPCON1 = %00101000
	SSPCON2 = 0
end sub

I think you'll find Swordfish is usually pretty good at generating code.

[slowfiddler]

Yes, that example would work just as well compiled from Basic. Actually, what I am trying to do is encapsulate some pretty tight atomic assembler routines from my existing product into Swordfish functions. Some of the routines have a lot of bitmasks that I would rather not convert to hex by hand.

[slowfiddler]

Well well! This works:

Code: Select all

Sub Init()
Asm

movlw      00101000B
movwf      SSPCON1
clrf       SSPCON2

End Asm
End Sub

Init()

end

nnnnnnnnB is an obsolete way of entering binary numbers in MPASM according to the GPUtils docs.

Happy now.