Bug 591

Two yosys 'custom technology cell map' files/scripts need to be created of 1) a 512 Byte yosys generated DFF SRAM, so it can be used properly by the coriolis workflow 2) Staf's SRAM block as an opaque VHDL simulation model (specifying only inputs/outputs/ports) so that it can be used by lkcl and others not under NDA to test soclayout/experiment12 and future soclayout work.

I have set the deadline for this bug as Friday 12 FEB 2021 because lkcl communicated to me that this will become a blocker shortly, once a certain part of JP's work has been completed.

"Cole: I think this stackoverflow question and answer may provide the process needed to do this: https://stackoverflow.com/questions/60143268/how-to-create-a-custom-technology-cell-map-for-yosys": https://bugs.libre-soc.org/show_bug.cgi?id=502#c15

Note that Dave Shah has commented on the answer so it seems like it's the right process."

"Staf: As asked in http://lists.libre-soc.org/pipermail/libre-soc-dev/2020-December/001451.html below is a generic SRAM simulation model in VHDL. I had to adapt the model for multiple WE bits so the model is not fully tested. It does analyze with ghdl though...": https://bugs.libre-soc.org/show_bug.cgi?id=502#c8

"Staf: I propose to use Verilog files to define blackboxes for yosys. This would as follows for the SRAM bock...": https://bugs.libre-soc.org/show_bug.cgi?id=502#c17