[libre-riscv-dev] [Bug 154] Cell for Dependency Matrices is needed

[Jacob Lifshay]

On Mon, Jan 13, 2020 at 6:00 AM Hendrik Boom <hendrik at topoi.pooq.com> wrote:
>
> On Sun, Jan 12, 2020 at 11:34:23PM +0000, bugzilla-daemon at libre-riscv.org wrote:
> > http://bugs.libre-riscv.org/show_bug.cgi?id=154
> >
> > --- Comment #2 from Luke Kenneth Casson Leighton <lkcl at lkcl.net> ---
> > here is a comparison between the truth tables of SR NOR and SR NAND
> >
> > <snip>
>
> One is not just the dual of the other; in particular, SR NAND has an invalid state whereas SR NOP does not.
> I don't know whether this is an important distinction or a typo.

It's a typo, they should be duals of each other (assuming they are the
simple 2-gate SR latch).

> The other thing I don't know, being a novice in hardware matters,
> is what "Latch" means as the output of a circuit.

Latch means that the output keeps its state from the instant before --
this is the simplest kind of gate-based digital memory.

Jacob