Chipworks has opened up and detailed the S1 computer-on-a-chip at the heart of the Apple Watch.

The Chipworks report goes a bit further than the teardown that appeared last week. This latest investigation from Chipworks reveals, among other things, that the application processor inside the Apple Watch's S1 is made using Samsung's 28 nanometer process. As a comparison, the Apple A8 system-on-a-chip is built with a 20nm process.

Here are some of Chipworks' more interesting (if highly technical) findings so far:

  • The new Apple APL0778 application processor measures 5.2 mm x 6.2 mm and is fabbed on Samsung's 28 nm LP process.
  • Dialog has the PMIC socket for the watch, but Maxim got the codec and amplifier sockets. What happened to Cirrus? They had been the incumbent in iPhones and iPads for several generations.
  • NXP scored the NFC and secure element and interface socket and Austria Micro Systems got the NFC signal booster
  • STMicroelectronics not only grabbed the 6-axis sensor, but they also have an ST32 MCU within the S1, as well as the optical emitter/sensor encoder die under the shaft of the Digital Crown.
  • Texas Instruments has 6 wins in the S1 ranging from battery management to opp amps.
  • Skyworks Wi-Fi LNA + switch and PA
  • Above you see a composite image of all the dies we have been able to identify so far.

As noted last week one of the more intriguing aspects of the S1 is its complete lack of dynamic random access memory (DRAM), which is found in most computers, including Apple's iPhone and iPad. The S1 appears to have 512MB of static random access memory (SRAM).

The S1 stands as a contrast to Apple's previous custom silicon, such as the A8. While the A-series processors combine a device's CPU, GPU, and RAM onto a single die, the S1 holds an entire computer system into one sealed package.

chipworks S1 teardown

Source: Chipworks