Olin Lathrop wrote:
>
> I have no idea what you mean by "vertically stacked data".  Data is in
> RAM.  Left, right, up, and down orientations are rather meaningless.

Data is aligned vertically, i.e. each byte is carrying similar
position bits from different vertically oriented "normal" bytes.

Example:
a=0b00111010 b=0b11010110 c=0b01100011 d=0b10001011

being vertically aligned will become:
LSB
0011=e
1111=f
0100=g
...
0110=k
0101=l
^^^^
abcd
MSB

Actually very helpful when you do math on 8 bytes 6 bits each ;)


> You have 8 bytes of data you want to add, so just add them.  The PIC can
> do an 8 bit add in one instruction.  What's the problem?

Horizontal carry is propagating withing one byte from right to the left
while vertical carry is propagating to next level for 8 bits simultaneously.
Vertical math is faster for some circuimstances.

Scott does have a nice illustration on his website.
And this is also just fun after all. ;)


WBR Dmitry.

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