[Arm-netbook] libre 64-bit risc-v SoC

[David Niklas]

On Mon, 8 May 2017 06:24:08 +0100
Luke Kenneth Casson Leighton <lkcl at lkcl.net> wrote:
> On Mon, May 8, 2017 at 4:00 AM, David Niklas <doark at mail.com> wrote:
<snip>
> >> > important to avoid, because mixed analog and digital is incredibly
> >> > hard to get right.  also note that things like HDMI, SATA, and even
> >> > ethernet are quite deliberately NOT on the list.  Ethernet RMII
> >> > (which is digital) could be implemented in software using a minion
> >> > core.  the advantage of using the opencores VGA (actually LCD)
> >> > controller is: i already have the full source for a *complete*
> >> > linux driver.  
> >
> > Considering that analog was around *long* before digital I'm surprised
> > that it is "Hard to get right",  
> 
>  analog isn't "hard".  digital isn't "hard".  specifically *MIXING*
> them is ultra-hard.
> 
> > is there a reason for this?  
> 
>  completely different processes and design criteria.  the restrictions
> (design rules) placed on digital ASIC layouts have to be adhered to in
> the *analog* areas: you can't just change the stack to suit the analog
> areas.  i don't know the full details, but i know someone with 30
> years experience of working with ASICs who does.
> 
> > Isn't there a chip for just this kind of thing?  
> 
>  no.  not a custom one... and we're taking custom ASICs.

Forgive me for contradicting you again, but don't all computers that have
a MIC in jack using some sort of analog to digital converter?
And vice-versa with Headphone out?
I think they all use PCM.
Would such a converter be suitable? Why?


Thanks,
David