Difference between hard macro, partition block and black box

[ssti85]

Hello All,

What is the difference between hard|soft macro, partition block and black box.

Also, when we talk about the placement status of a block, what is the difference between placed and fixed? Also, what is 'cover' in the same context?

I understand that 'unplaced' will allow the macro to be auto placed by the auto placement algorithms.. Is that right?

Thank you..

 

[rca]

black box: is a macro the tool didn't have any timing/power/functional view.

hard macro is a memory for example.

patirtion block? did you mean patirtion blockage?

placed versu fixed, when fixed, the tool can not move it, placed, he can, like unplaced, but I did not know if in placed mode, the tool will only move during optimisation phase, and not move during first placement phase ?

Cover: is used when you have a macro not rectangle. For example, the macro shape is a "U", the lef will indiacate via the "SIZE" keyword, the width and lenght, and via the layer BOUNDARY (example), indicate the "U" shape, the placer tool can't place any std cell inside the "U" if the macro is not placed with the cover attribut, instead, there is row and not metal/placement blockage.

 

[ssti85]

Re: Difference between hard macro, partition block and black

Hello rca,

Thank you for your reply. I'm actually working on a layout that also has a memory block as a hard macro, and use foundation flow scripts which I'm also editing for my application.

I was struggling with the placement of the mem block - and it was being re-placed in the floorplan (as its status was not 'fixed'). I realized that even if I manually changed the staus to 'placed', it wouldn't help.

So making it 'fixed' was the only solution.

Thank you for your reply though.
Great explanations.

Thanks again.