Question: Jim Keller is a microprocessor engineer most well known for his work at AMD and Apple, he was involved in designing which 32-bit package on package (PoP) system-on-a-chip (SoC) designed by Apple Inc. and manufactured by Samsung? 
Sentence (from "Apple A4"): The chip commercially debuted with the release of Apple's iPad tablet; followed shortly by the iPhone 4 smartphone, the iPod Touch (4th generation), and the Apple TV (2nd generation).
Relevant evidence: No