[Arm-netbook] HDMI High-Frequency Layout: Timing

[Richard Wilbur]

On Tue, Aug 1, 2017 at 8:11 AM, Luke Kenneth Casson Leighton
<lkcl at lkcl.net> wrote:
> On Tue, Aug 1, 2017 at 2:51 PM, mike.valk at gmail.com <mike.valk at gmail.com> wrote:
>> Found a nice post from TI
>> https://e2e.ti.com/blogs_/b/analogwire/archive/2015/06/10/differential-pairs-four-things-you-need-to-know-about-vias
>
>  nice!  dang, above 10ghz the thickness of the via starts to matter
> and needs to be drilled out, post-production.  dang.

Since we're not trying to support HDMI post v1.4 we don't have signals
above 10GHz on this interface at least.  Thankfully none of the signal
trace vias need to be drilled out since our signals always traverse
the whole via.

>  *sigh* unfortunately symmetry is not completely achievable with the
> drastically-reduced amount of space available.  the HDMI signals come
> out right at the bottom of the board.

Hopefully most of what we can't accomplish with symmetry we can remedy
with creativity.