OpenLANE Tools

Open the virtual machine. I used VMWare Workstation Pro, but you can use any other software you want.

warning

Mac support on Apple Silicon devices is not as good as Linux/Windows/Intel Macs. It is suggested to either:

A: use a different device. B: install Parallels or some other software that supports Apple Silicon Macs.

Start the Tools

Make sure you are in /home/vsduser/Desktop/work/tools/openlane_working_dir/openlane.

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

# create this alias so you don't need to type the long command
alias docker='docker run -it -v $(pwd):/openLANE_flow -v $PDK_ROOT:$PDK_ROOT -e PDK_ROOT=$PDK_ROOT -u $(id -u $USER):$(id -g $USER) efabless/openlane:v0.21'

# open the docker environment
docker

# enable interactive mode
./flow.tcl -interactive

# load openlane package
package require openlane 0.9

# prep and run your design
prep -design picorv32a

Run Everything

Synthesis

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

# run the synthesis. this will display a lot of text in the terminal.
# it will tell you if it was a success at the end.
run_synthesis

Calculate the Flop Ratio

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

All the files generated are stored in the reports/ directory. Open it and see what's there! The reports from run_synthesis are stored in synthesis/. Open the folder and run ls -l to see the files.

Run cat 1-yosys_4.stat.rpt to see the synthesis statistics. We will use this to make our calculations.

warning

The numbers in your file may be different. However, the calculation process is still the same.

    Number of wires:                14596
    Number of wire bits:            14978
    Number of public wires:         1565
    Number of public wire bits:     1947
    Number of memories:             0
    Number of memory bits:          0
    Number of processes:            0
    Number of cells:                14876

    [content hidden]

        sky130_fd_sc_hd__conb1      42
        sky130_fd_sc_hd__dfxtp_2    1613
        sky130_fd_sc_hd__inv_2      1615

    [content hidden]

$Flop \space Ratio = \frac{\# \space of \space D \space flip\space flops}{Total \space \# \space of \space cells}$

$\% \space of \space DFFs = Flop \space Ratio \times 100$

$Flop \space Ratio = \frac{1613}{14876} \approx 0.10843$

$\% \space of \space DFFs = 0.10843\times 100 = 10.843 \%$