Question when Memory placing in floorplan

[JasonJung]

Hey,
I am just a newbie in asic design. ( I just started working as a PnR engineer)
When I was in University, I remember that there was a concept of memory mapping... where several memory units share address bus and each emory unit is selected by some MSBs of address bits(Maybe the data in bus also shared). some thing like the below pic

The reason I suddenly thought about this was ... when I was working on my block.. there were so many memory macros and when I was placing those the fact I mentioned above hit my mind.

So my question is when there are many memorys in the block, will there be cases like the memory macros share the address bits or data bits ? (If yes i think its better to put those related ones close)

 

[Qwerty112233]

That's a good point to keep in mind, you dont want these srams to be on opposite edges of the core for example.

But usually RTL hierarchy names help you understand what macros need to be close to each other, then next thing you can look for is their instance names if they have _lo _hi , that could guide you to keep these two close.

Keeping a close loop with designer or reading the RTL helps in this fine tuning. But first order, its good enough to go by RTL module names.

 

[JasonJung]

That's a good point to keep in mind, you dont want these srams to be on opposite edges of the core for example.

But usually RTL hierarchy names help you understand what macros need to be close to each other, then next thing you can look for is their instance names if they have _lo _hi , that could guide you to keep these two close.

Keeping a close loop with designer or reading the RTL helps in this fine tuning. But first order, its good enough to go by RTL module names.

thanks,
by the way what is meant by _lo , _hi
in instance name?

 

[ThisIsNotSam]

option 1: talk to the person that wrote the RTL to have a good understanding of which memory is related to which memory
option 2: start with an automatically generated floorplan and see if any patterns emerge. refine the floorplan based on that