Wilsonville, Oregon-based semiconductor software firm Mentor Graphics said today that it has acquired another firm in the industry, Sierra Design Automation. Mentor said it will pay $90M in stock and cash for the company, a provider of high-performance place and route software used in the semiconductor design flow. Mentor said that the acquisition will allow it to provide place-and-route solutions for 65 and 45 nanometer designs. Both Mentor Graphics and Sierra Design Automation develop software used in semiconductor design.