Most Microprocessor manufacturers Atmel, Microchip, ST, TI, NXP etc give out incredible documentation for free and probably enough though for a competitor to reverse engineer a dodgy but functional implementation of the chip (say in a FPGA).
Not sure why these guys go all the way where as companies like broadcom do not, I would put it more to shaving the last cent off the chip. I know which ones I would choose as an engineer but you dont often get to make the choice.
Considering that automotive fault tolerance is one of NXP's core competences, I can guarantee you that there is plenty of secret sauce that you're not privy to in those chips.
Not sure why these guys go all the way where as companies like broadcom do not, I would put it more to shaving the last cent off the chip. I know which ones I would choose as an engineer but you dont often get to make the choice.