Timing scripts

A set of scripts for rcx and sta for caravel top level

Dependencies

  • Docker

In case of not using the docker image:

  • yosys
  • Python modules:
    • click

Prerequisites

A set of exports are needed:

export CARAVEL_ROOT=${HOME}/caravel/
export MCW_ROOT=${HOME}/caravel_mgmt_soc_litex/
export CUP_ROOT=${HOME}/caravel_user_project/
export TIMING_ROOT=${HOME}/timing-scripts/
export PDK_ROOT=${HOME}/pdk/
export PDK=sky130A
export OPENLANE_IMAGE_NAME=efabless/openlane:4476a58407d670d251aa0be6a55e5391bb181c4e-amd64

This is just an example. Please export your own paths and a recent version of openlane

Usage

caravel_user_project

  1. After exporting the prerequisites, run:

    make -f timing.mk list-rcx
    

    You should get rcx-user_project_wrapper amongst others such as:

    rcx-buff_flash_clkrst
    rcx-caravel
    rcx-caravel_clocking
    rcx-constant_block
    rcx-digital_pll
    rcx-gpio_control_block
    rcx-gpio_defaults_block
    rcx-gpio_logic_high
    rcx-gpio_signal_buffering
    rcx-gpio_signal_buffering_alt
    rcx-housekeeping
    rcx-mgmt_protect
    rcx-mprj2_logic_high
    rcx-mprj_logic_high
    rcx-spare_logic_block
    rcx-RAM256
    rcx-mgmt_core_wrapper
    rcx-user_proj_example
    rcx-user_project_wrapper
    
  2. extract multicorner spefs for user_project_wrapper and any other blocks inside:

    make -f timing.mk rcx-user_project_wrapper
    make -f timing.mk rcx-user_proj_example
    
  3. generate spef mapping file for caravel_user_project:

    python3 ./scripts/generate_spef_mapping \
        -i ${CUP_ROOT}/verilog/gl/user_project_wrapper.v \
        -o ${CUP_ROOT}/env/spef-mapping.tcl \
        --project-root '$::env(CUP_ROOT)' \
        --pdk-path "${PDK_ROOT}/${PDK}"
    
  4. run sta:

    make -f timing.mk caravel-timing-typ
    make -f timing.mk caravel-timing-slow
    make -f timing.mk caravel-timing-fast
    

Limitations

  • Makefile
  • Makefile
  • Assumes a fixed folder structure for the exported directories
  • Probably a lot of corner cases that weren't considered