FBI Director Comey has admitted the only Apple devices the FBI can unlock, and that with a lot of work, are Apple devices with A6 processors and older. Essentially that means the iPhone 5c, 5, and older, the original iPad Air and the original iPad Mini, and any older iPads. Of course the older iPhones and iPads were not protected with encryption at all. That innovation came in with the iPhone 5 and 5C with the A6 processor with the Encryption Engine sub-processor built into the Processor SoC.
The A7 and later processors were designed to use the Secure Enclave system which is far more secure.
I never knew Apple used AMD A6 processors???