Floorplanning in OpenLANE

Create the Floorplan

Make sure you ran the command specified in Day 1:

vsduser@vsdsquadron: ~/Desktop/work/tools/openlane_working_dir/openlane

docker
./flow.tcl -interactive
package require openlane 0.9
prep -design picorv32a
run_synthesis

Run the floorplan:

vsduser@vsdsquadron: ~/Desktop/work/tools/openlane_working_dir/openlane

run_floorplan

Calculate Die Area

Open ~/Desktop/work/tools/openlane_working_dir/openlane/designs/picorv32a/runs/<latest run>.

Open results/floorplan/.

Run nano picorv32a.floorplan.def to view the reports.

    VERSION 5.8 ;
    DIVIDERCHAR "/" ;
    BUSBITCHARS "[]" ;
    DESIGN picorv32a ;
    UNITS DISTANCE MICRONS 1000 ;
    DIE AREA ( 0 0 ) (660685 671405) ;


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We know that 1000 units = 1 micron.

• The die width in units: $660685 - 0 = 660685$.
• The die height in units: $671405 - 0 = 671405$.

To convert to microns: $\frac{Units}{1000}$

• The die width in microns: $\frac{660685}{1000} = 660.685$ microns.
• The die height in microns: $\frac{671405}{1000} = 671.405$ microns.

Die area in microns = $length \times width = 660.685 \times 671.405 = 443587.212425 \space microns^{2}$

View the Floorplan in Magic

Let's open the floor plan in Magic. Make sure that you are in the same directory as you were before for the floorplan.

vsduser@vsdsquadron: ~/Desktop/work/tools/openlane_working_dir/openlane

magic -T /home/vsduser/Desktop/work/tools/openlane_working_dir/pdks/sky130A/libs.tech/magic/sky130A.tech lef read ../../tmp/merged.lef def read picorv32a.floorplan.def &

tip

You can hit S on your keyboard to select the chip. Then, hit V to scale it to the entire window size (zoom in).

Placement of ports:

Standard cells that haven't been placed remain at the origin:

Run the Placement

vsduser@vsdsquadron: ~/Desktop/work/tools/openlane_working_dir/openlane

# run the placement
run_placement

# open generated placement def
cd Desktop/work/tools/openlane_working_dir/openlane/designs/picorv32a/runs/{date}/results/placement/

# open with magic
magic -T /home/vsduser/Desktop/work/tools/openlane_working_dir/pdks/sky130A/libs.tech/magic/sky130A.tech lef read ../../tmp/merged.lef def read picorv32a.placement.def &

Zoomed in view: