Apple continues to use its A series processors in its iPhones and iPads, but the company might have infringed on a patent held by the University of Wisconsin on some of its older chips.

Apple used the A7, A8 and A8X processors in the iPhone 5s, the iPhone 6, the iPhone 6 Plus and some iPads. A U.S. District Court jury ruled on Tuesday that those chips infringed on a 1998 patent held by the University of Wisconsin, and the tech company could now face fines of over $800 million, CNet reports.

The University of Wisconsin first filed the suit back in January 2014. Apple argued that the university's patent was invalid and tried to convince the U.S. Patent and Trademark Office to review it, but a jury in Wisconsin found the patent to be valid.

Apple has also argued over patents with Samsung over the past several years. Originally, Samsung was ordered to pay Apple over $1 billion in 2012 over claims that most of Samsung's phones copied technology used by Apple. After several appeal hearings, the two companies will return to court in 2016 to try to make a settlement.

It is unclear how much Apple will have to pay to the University of Wisconsin, and the amount could go down if Apple appeals. However, if the court finds that Apple purposely infringed on the patent, damages could go up. The university has said that Apple would not accept their offers to license the patent, which would have required the manufacturer to pay a fee.

Another lawsuit was recently started by the university concerning the latest chips from Apple, the A9 and the A9X. The A9 is found inside the iPhone 6s and iPhone 6s Plus, while the A9X will be used in the new iPad Pro.

The $862 million the company may have to pay the university represents only a small percentage of Apple's $18 billion reported quarterly profit.