Apple also served notice that as a result, it intends to stop making royalty payments, Imagination said in a statement. Imagination's stock price on the London Stock Exchange fell by more than 60 percent.
This follows on from the exclusive story that Apple had been hiring several Imagination GPU design engineers in the second half of 2016 (see Apple hires group of UK GPU engineers ).
However, Imagination said that Apple had declined to give any evidence that it could be designing a separate, independent graphics design that would not violate Imagination's patents, intellectual property and confidential information.
Apple has used has used PowerVR cores licensed from Imagination in its A-series application processors and its IP more generally for many years. Imagination GPUs have formed the basis of GPUs in Apple's phones, tablets, iPods, TVs and watches. Apple helped bail out Imagination in the past and became a minority shareholder in the company as a result.
However, during the last crisis in 2016, which saw the departure of Imagination CEO Sir Hossein Yassaie, Apple said that although it had held talks with Imagination it did not plan to make an offer for the company (see Apple has no plans to buy Imagination ).
Apple could have gone for the option of designing its own custom GPUs under an architectural license from Imagination. This is a route it has gone down with ARM on the main processor cores. However, Apple appears determined to cut itself free from the troubled graphics chip company.
In its statement Imagination said it believes it would be extremely challenging to design a new GPU architecture from basics without infringing Imagination intellectual property rights and does not accept Apple’s assertions.
Imagination said it has held discussions with Apple over "potential alternative commercial arrangements for the current license and royalty agreement."
Related links and articles: