How to detemine which metal layer used for SRAM/subblock power ring?

[chris_li]

Hi Guy,

I am junior, I want to ask a foolish question, in general, selecting which layer for SRAM/subblock power ring? Is there any routine or experience?

Thanks.

 

[lohi21]

Hi Guy,

I am junior, I want to ask a foolish question, in general, selecting which layer for SRAM/subblock power ring? Is there any routine or experience?

Thanks.

Hi chris,

if you know, which metal layer is being used out SRAM/sub block, then prefer same metal for your ring creation.

but if your SRAM is a macro, then your approach would be different, and various factors to be considered before using any particular metal layer.

In general:
most likely the same metal layer as out side your block for mesh and/or if your design is working on single voltage domain.

 

[rca]

why do you want to have a dedicated power ring for each ram?, you could connect by a grid upper the RAM?
some ram have already an internal power ring, some not...