the meaning of local_array_size

[hanm2019]

I found that there is a parameter named local_array_size in freepdk45_sram_1r21r_32x2048_8.py, but I can not find any document which describes this parameter.

OpenRAM/macros/sram_configs/freepdk45_sram_1rw1r_32x2048_8.py

Line 5 in 0a4a364

local_array_size = 32

[mguthaus]

This parameter specifies the size of a local/sub array and uses a hierarchical word line. I don't believe it was working yet in sky130 due to a DRC error.

[hanm2019]

How should I config this parameter in FPDK45nm? set the value equal to the word_size?

[mguthaus]

I suggest you look at how it affects layout. Setting it to the word size is the default and will not use a hierarchical word line. Larger arrays can have a big word line delay and can benefit from this to improve speed.