At 05:30 AM 3/6/98 -0500, Walter Banks wrote:
>At least for the 16bit core with multiply the quickest divide by 3
>is to multiply by 0x55 and use the MS byte and add 1 if the LS byte
>is greater than 7F.
>
>This is ((256 / 3) / 256)
>
>Walter Banks

Since 0x55 is %01010101 in binary, try the following algorithm:

A is a 16-bit register
N is the 8-bit initial value, padded to 16 bits by adding a zero MSByte

Shift N left 1 bit
Put N in A
Shift N left 2 bits
Add N to A
Shift N left 2 bits
Add N to A
Shift N left 2 bits
Add N to A

Answer is now in high byte of A.

 - Rick "What's the fastest PIC implementation?" Dickinson

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