Apple's A7 SoC turned heads when it launched at the heart of the iPhone 5S, including some at the Wisconsin Alumni Research Foundation (WARF), a patent-licensing arm of the University of Wisconsin at Madison. WARF filed a lawsuit in January, 2014, alleging that Apple had infringed on one of the foundation's patents. The U.S. District Court for the Western District of Wisconsin heard that lawsuit in a jury trial, and the verdict is in: Apple did infringe on WARF's patent.
The patent in question was awarded in July 1998 for a type of branch prediction logic. The patented technology helps a CPU avoid mispredictions during out-of-order execution for instructions that would normally depend on data from earlier computations. According to the patent documents, the logic analyzes the results of prior mispredictions in order to predict and synchronize these dependent instructions, and it does so by keeping a table of each instance of such dependencies. The table entries can be dynamically added and deleted to keep memory requirements low.
Reuters reports the suit against Apple was later expanded to include the A8 and A8X SoCs, which are included in the finding of the jury. Apple could be on the hook for damages up to $862 million, pending appeal. Reuters also says WARF has launched a second lawsuit against Apple over the A9 SoC found in the iPhone 6S and 6S Plus, as well as the A9X at the heart of the iPad Pro.