[Arm-netbook] HDMI High-Frequency Layout: Recommendations--Taper

[Richard Wilbur]

On Sat, Dec 16, 2017 at 10:12 PM, Luke Kenneth Casson Leighton
<lkcl at lkcl.net> wrote:
> ... yyyyeahhh.... that looks better, doesn't it?


Strong work, Luke!  That does indeed look nice.

> the left outer track is shuffled forward by... errr.... sqrt(2) / 4 * 5mil
> the one in from that (HTX2P) doesn't need shuffling as it's right next
> to the green pair...
> the right outer one (HTXCN) by 3x that amount
> the next one in (HTXCP) by 2x that amount
> the next one in (HTX0N) by 1x that amount
> HTX0P is right next to the green pair which is dead-straight so
> doesn't need shuffling
>
> so if i've got this right, the separation gap intra-pair should remain
> at 5.0 mil, and when all the pairs get close together at the end they
> should again be exactly 5.0 mil apart even on the 45 degree bending.
>
> whewwww :)
>
> i think that's it (oh, except the step needs adjusting to 15mil not
> 5mil as it is now).  now i have to identify where in the PADS file the
> rectangle for the keepout area is, add *that* to the parser as well,
> then do the same maths and create a tethered keepout area.  *sigh*...

I'm sorry I didn't fill in more of the geometric considerations.
Looks like you have them in hand.

When the step offset is d, then the 45 degree step travel will be sqrt(2.0) * d.

Looks like you have the starting positions parallel which was the
intent but I did not specify the mathematics.  I didn't know what
origin or reference point and direction you would like to use.