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

[Richard Wilbur]

On Jan 5, 2018, at 23:49, Luke Kenneth Casson Leighton <lkcl at lkcl.net> wrote:
> 
> On Sat, Jan 6, 2018 at 6:35 AM, Richard Wilbur <richard.wilbur at gmail.com> wrote:
>> So the trick is how to choose a faster chip and integrate successfully into a system running at lower speed than it is specified for?
> 
> yyup.  have to use the 1800mhz 1.5v x8 DDR3 IC, which fortunately
> happens to be down-compatible with 667mhz.  the 1.35v DDR3L variant of
> the same chip is *not*.

I was doing a little reading about DDR3 and noticed the 1.35V DDR3L memory chips are happy talking/running with 1.5V DDR3 systems.[1]  So are you saying the 1800mhz 1.35v x8 DDR3L IC is not happy running at 667MHz?  (Clock rate incompatibility versus voltage incompatibility?)

References:
[1]  https://en.m.wikipedia.org/wiki/DDR3_SDRAM