Anand Lal Shimpi, writing for Anandtech:
“The A6 is the first Apple SoC to use its own ARMv7 based processor design. The CPU core(s) aren’t based on a vanilla A9 or A15 design from ARM IP, but instead are something of Apple’s own creation.”
This is Steve Jobs’ legacy: bit by bit, Apple reduces its dependance upon others. This time around, iPhone’s silicon is home-made IP.