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