Need to flip order of bits MSB to LSB re: MCP23S17

[Art]

Using two bytes (PBP alias) I don’t think costs you any time even behind the scenes,
and then just addressing them in the order you want would be the next best thing to swapping the hardware.
I’m not familiar with the device, but if REV didn’t work as you expected, it sound like swapping bytes was the solution?

If that’s wrong, and it’s back to reversing bits, there’s no math to do it,
it’s always whacky procedural code emulating what a Human would do.
You can use the above method first (almost free), and then logical operators,
but it’s essentially the same goal as moving a ball around a table with paper cups.

[Art]

I’ve got to do it this weekend, and don’t get to use REV, so this is what I came up with (untested).
There’s another thread about REV somewhere.. it was decompiled to find out instruction time,
and I don’t know right now If I’m beating it.

sixteenbit var word
revsixteen var word

leasteight var sixteenbit.byte0
mosteight var sixteenbit.byte1
leastrev var revsixteen.byte0
mostrev var revsixteen.byte1

count var byte


reversesixteen:

for count = 0 to 7

leastrev.bit7 = mosteight.bit0
mosteight << 1
leastrev >> 1

mostrev.bit7 = leasteight.bit0
leasteight << 1
mostrev >> 1

next count

return