A disassembly of the iPhone found it to be very precisely designed. Multiple CPUs take on different tasks, and software functionality has been chosen in preference to hardware performance. It’s doubtful that there’s a large degree of automated assembly in China, according to EDN.

What was most impressive was the use of the volume, getting Wi-Fi, BlueTooth, GSM cellular data and voice, a position sensor, a CPU, and a lot of volatile and nonvolatile memory into a very small package. EDN’s Senior Technical editor, with help from Portelligent, said that anyone would be impressed with Apple’s electrical and mechanical engineering teams.

The 3.7V lithium-ion battery takes up a considerable about of the iPhone’s volume which makes the design all the more impressive.

The key components are:

• ARM1176JZF with TrustZone, with a clock at perhaps 600 MHz
• ARM Intelligent Energy Manager
• 16-kbyte/16-kbyte code/data cache
• Vector floating point coprocessor
• ARM Jazelle-enabled for embedded-Java execution
• SIMD high performance integer CPU with an eight-stage pipeline, capable of 675 Dhrystones/sec and 2.1 MIPS
• 0.45 mW/MHz power draw (with cache)

Also of note is the partition of tasks in the iPhone. It appears that the iPhone has multiple CPU units that subdivide tasks and take on different roles. When those units aren’t engaged, they can be powered down.

It also appears the Apple engineers made a conscious decision to not rely too much on hardwired circuits -- even though they would deliver higher performance and lower power consumption. The goal seems to have been to trade that against increased future flexibility and functionality with software. That’s something we all suspected, but is now confirmed.

There is much more detail in the tear down report, and it is notable for its engineering detail, perhaps even more detail than many will want to know about the iPhone internals.