[Libre-soc-dev] [SVP64] feedback needed - Pack/Unpack (vpack/vunpack)

[Jacob Lifshay]

On Fri, Aug 12, 2022, 18:35 lkcl via Libre-soc-dev <
libre-soc-dev at lists.libre-soc.org> wrote:

> i think it was that the uniformity promised by SimpleV cannot
> be provided here.  i would love to be able to use EXTRA3 encoding
> *and* still have 2 bits spare for Pack/Unpack but there are only
> 9 bits in RM.EXTRA.
>
> src extra3 3 bits
> dest extra3 3 bits
> pack/unpack 2 bits
> dest elwidth 2 bits
>
> that's 10.


how about requiring dest elwidth == src elwidth when pack/unpack is
enabled, allowing you to use 1 bit for enabling pack/unpack, and the now
available dest elwidth field for selecting what kind of pack/unpack you
want? this allows it to fit in 9 bits.

Jacob