Apple S1

The Apple S1 is the integrated computer in the first-generation Apple Watch, and it is described as a "System in Package" (SiP) by Apple Inc.^[7]

Apple S1

The S1 integrated computer, 2.5 cm wide[1]
General information
Launched	13 November 2014
Discontinued	7 September 2016
Designed by	Apple Inc.
Common manufacturer	Samsung[2]
Product code	APL0778[3]
Performance
Max. CPU clock rate	520 MHz[4]
Cache
L1 cache	32 KB data[4]
L2 cache	256 KB[4]
Architecture and classification
Application	Apple Watch
Technology node	28 nm[4][2]
Instruction set	ARMv7-A[4]
Physical specifications
Cores	1[4]
GPU	PowerVR SGX543[5]
Products, models, variants
Variant	Apple S1P
History
Successor	Apple S2

Apple S1P

General information
Launched	September, 2016
Discontinued	September, 2018
Designed by	Apple Inc.
Performance
Max. CPU clock rate	520 MHz[6]
Architecture and classification
Application	Apple Watch Series 1
Microarchitecture	ARMv7-A compatible[6]
Instruction set	ARM[6]
Physical specifications
Cores	2[6]
GPU	PowerVR Series 6 'Rogue'[6]
History
Predecessor	Apple S1

Samsung is said to be the main supplier of key components, such as the RAM and NAND flash storage, and the assembly itself,^[8] but early teardowns reveal RAM and flash memory from Toshiba and Micron Technology.^[3]

System-in-Package design

It uses a customized application processor that together with memory, storage and support processors for wireless connectivity, sensors and I/O constitute a complete computer in a single package. This package is filled with resin for durability.^[9]

Components

From reverse engineering, the processor handling the Wi-Fi and Bluetooth is a Broadcom BCM43342^[10] and the six-axis gyroscope is from STMicroelectronics.^[2]

• Apple designed 32-bit ARMv7^[11] based application processor APL0778 as the central processing unit (CPU), with an integrated PowerVR SGX543 graphics processing unit (GPU).^[5]
• 512 MB DRAM from Elpida, wire bonded on top of the APL0778 CPU
• NFC controller from NXP
• NFC booster chip from AMS
• 8 GB flash from SanDisk and Toshiba
• Wireless charging chip from IDT
• Touch controller from ADI
• Integrated gyro/accelerometer from STMicroelectronics
• BCM43342 Wi-Fi/FM/BT combo chip from Broadcom
• Power management unit (PMU) from Dialog Semiconductor

S1P

The SiP in Apple Watch Series 1 is called S1P and looks superficially identical to the S1, but in reality is an S2 minus the on-chip GPS functionality. It contains the same dual-core CPU with the same new GPU capabilities as the S2 making it about 50% faster than the S1.^[12][13]

Announcement

The S1 was announced on 9 September 2014 as part of the "Wish we could say more" event.

The S1P was announced on 7 September 2016 as part of the "See you on the 7th" event.

Launch date

The S1 made its first appearance within the Apple Watch, which arrived in April 2015.^[7][14] The S1 was discontinued with the launch of Apple Watch Series 1, containing the S1P.

The S1P was released with the Apple Watch Series 1 on 16 September 2016.^[13]

Images

• 
  An illustration of the encapsulated S1 package^[9][15]
• 
  The S1P package shows little of the differences that's encapsulated inside.
• 
  This illustration shows the positions of the chips and other components inside the S1 package.^[15]
• 
  This is how large the S1 is compared to the Apple Watch case.^[15]
• 
  A size comparison of the S1 to the Apple A6 in the iPhone 5^[15]

See also

• Apple silicon, the range of ARM-based processors designed by Apple.
• Apple Watch
• Apple S2