updated 03:29 pm EDT, Tue March 12, 2013
Chip represents new hardware
The new, smaller A5 chip in recent Apple TVs is actually still a Samsung design, and still built using a 32nm process, says semiconductor analysis firm Chipworks. Initial examination suggested that the processor had switched to 28nm, which might also have pointed to TSMC as the responsible manufacturer. The new information indicates that Apple has redesigned the processor, and not just shrunken it.
If any functionality is different though, it's not yet apparent. The A5 continues to go without stacked DRAM, which another firm, Silicon-IP, argues may simply mean that Apple hasn't yet lined up a process for package-on-package design. Chipworks speculates that the new chip may yet be part of a "pipe-cleaner" run for handing over some A-series production to TSMC, giving Apple a reference and/or fallback option while TSMC works on new silicon.
Why Apple would need to redesign the A5 is otherwise unknown, given that the Apple TV, iPad 2, iPad mini, and fifth-generation iPod touch are all already equipped with it. The company could be planning to use the chip in a rumored low-cost iPhone, where space might be at a premium.