| # Copyright 2023 Google LLC |
| # Copyright lowRISC contributors |
| # |
| # Licensed under the Apache License, Version 2.0 (the "License"); |
| # you may not use this file except in compliance with the License. |
| # You may obtain a copy of the License at |
| # |
| # http://www.apache.org/licenses/LICENSE-2.0 |
| # |
| # Unless required by applicable law or agreed to in writing, software |
| # distributed under the License is distributed on an "AS IS" BASIS, |
| # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| # See the License for the specific language governing permissions and |
| # limitations under the License. |
| # |
| # While the code below looks messy, it was taken directly from a vivado example |
| # See here (https://www.xilinx.com/support/answers/66386.html) |
| # See also this link (https://github.com/lowRISC/opentitan/pull/8138#issuecomment-916696830) |
| # for a thorough explanation of why such a custom placement helps. |
| # Note the placement location was not chosen through any systematic means, but through trial |
| # and error, it may become necessary in the future to tweak this if other congestion |
| # issues arise. |
| |
| ## Delete placement constraint for now since it helps timing closure, but will keep the file for now. |