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

Richard Wilbur richard.wilbur at gmail.com
Fri Aug 11 00:37:35 BST 2017


On Wed, Aug 9, 2017 at 7:23 AM, Luke Kenneth Casson Leighton
<lkcl at lkcl.net> wrote:
> next set...
>
> wiggles.jpg is the layer 6 length-matching area: HX2N/P is the one
> that's the longest, it snakes back on itself.  i length-matched all 3
> signal pairs to 56.413, and left the CK lines at 57.134 just to give
> the tiniest bit of delay (TI recommendations iirc).

Very nicely done!  57.134mm - 56.413mm = 721um
=> T(delay) = 721um / 150um/ps = 4.8ps

That is a very tiny delay!  Now that we have achieved such close
synchronization, I'm suggesting we go for the next goal where we
design a certain amount of inter-pair skew into the layout for
purposes of lowering the strength of our synchronized pulsing data
lines to a more diffuse chatter.

> no - not even enough space to do 5.1mil / 5.0 clearance... just...  too much.

I understand.  We might end up with more room--see discussion below.

> the other images show the via'd portions, they're all either
> symmetrical or perfectly length-matched to 0.001mm.

Again, they look nice.<div id="DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2"><br />
<table style="border-top: 1px solid #D3D4DE;">
	<tr>
        <td style="width: 55px; padding-top: 13px;"><a
href="http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail"
target="_blank"><img
src="https://ipmcdn.avast.com/images/icons/icon-envelope-tick-green-avg-v1.png"
alt="" width="46" height="29" style="width: 46px; height: 29px;"
/></a></td>
		<td style="width: 470px; padding-top: 12px; color: #41424e;
font-size: 13px; font-family: Arial, Helvetica, sans-serif;
line-height: 18px;">Virus-free. <a
href="http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail"
target="_blank" style="color: #4453ea;">www.avg.com</a>
		</td>
	</tr>
</table><a href="#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2" width="1"
height="1"></a></div>



More information about the arm-netbook mailing list