The Apple A4 is a 32-bit package on package (PoP)

system on a chip A system on a chip or system-on-chip (SoC ; pl. ''SoCs'' ) is an integrated circuit that integrates most or all components of a computer or other electronic system. These components almost always include a central processing unit (CPU), memor ...

(SoC) designed by Apple Inc. and manufactured by

Samsung The Samsung Group (or simply Samsung) ( ko, 삼성 ) is a South Korean multinational manufacturing conglomerate headquartered in Samsung Town, Seoul, South Korea. It comprises numerous affiliated businesses, most of them united under the ...

. It was the first SoC Apple designed in-house. The first product to feature the A4 was the first-generation iPad, followed by the

iPhone 4 The iPhone 4 is a smartphone that was designed and marketed by Apple Inc. It is the fourth generation of the iPhone lineup, succeeding the iPhone 3GS and preceding the 4S. Following a number of notable leaks, the iPhone 4 was first unve ...

, fourth-generation iPod Touch, and second-generation Apple TV. The last operating system update Apple provided for a mobile device containing an A4 (

) was iOS 7.1.2, which was released on June 30, 2014 as it was discontinued with the release of iOS 8 in September 2014. The last operating system update Apple provided for an Apple TV containing an A4 ( second-generation Apple TV) was Apple TV Software 6.2.1, which was released on September 17, 2014.

Design

Apple engineers designed the A4 chip with an emphasis on being "extremely powerful yet extremely power efficient." The A4 features a single-core

ARM Cortex-A8 The ARM Cortex-A8 is a 32-bit processor core licensed by ARM Holdings implementing the ARMv7-A architecture. Compared to the ARM11, the Cortex-A8 is a dual-issue superscalar design, achieving roughly twice the instructions per cycle. The Corte ...

central processing unit A central processing unit (CPU), also called a central processor, main processor or just processor, is the electronic circuitry that executes instructions comprising a computer program. The CPU performs basic arithmetic, logic, controlling, an ...

(CPU) manufactured on Samsung's 45 nm fabrication process using performance enhancements developed by chip designer Intrinsity (which was subsequently acquired by Apple) in collaboration with

. The resulting CPU, dubbed "

Hummingbird Hummingbirds are birds native to the Americas and comprise the biological family Trochilidae. With about 361 species and 113 genera, they occur from Alaska to Tierra del Fuego, but the vast majority of the species are found in the tropics ar ...

", is able to run at a far higher clock rate than previous Cortex-A8 CPUs while remaining fully compatible with the Cortex-A8 design provided by ARM. The same Cortex-A8 used in the A4 is also used in Samsung's S5PC110A01 SoC. The A4 also features a single-core PowerVR SGX535

graphics processing unit A graphics processing unit (GPU) is a specialized electronic circuit designed to manipulate and alter memory to accelerate the creation of images in a frame buffer intended for output to a display device. GPUs are used in embedded systems, mo ...

(GPU). The die of the A4 takes up 53.3 mm² of area. The

clock rate In computing, the clock rate or clock speed typically refers to the frequency at which the clock generator of a processor can generate pulses, which are used to synchronize the operations of its components, and is used as an indicator of the ...

of the Cortex-A8 in the A4 used inside the first-generation iPad is 1 GHz. The clock rate of the Cortex-A8 in the A4 used inside the

and fourth-generation iPod Touch is 800 MHz ( underclocked from 1 GHz). It is unknown what the clock rate of the Cortex-A8 in the A4 used inside the second-generation Apple TV is. The A4 uses the

PoP Pop or POP may refer to: Arts, entertainment, and media Music * Pop music, a musical genre Artists * POP, a Japanese idol group now known as Gang Parade * Pop!, a UK pop group * Pop! featuring Angie Hart, an Australian band Albums * ''Pop'' (G ...

method of installation to support RAM. The top package of the A4 used inside the first-generation iPad, the fourth-generation iPod Touch, and the second-generation Apple TV contains two 128 MB LPDDR chips, providing a total of 256 MB of RAM. The top package of the A4 used inside the iPhone 4 contains two 256 MB LPDDR chips, providing a total of 512 MB of RAM. The RAM is connected to the A4 using ARM's 64 bits wide AMBA 3 AXI

bus A bus (contracted from omnibus, with variants multibus, motorbus, autobus, etc.) is a road vehicle that carries significantly more passengers than an average car or van. It is most commonly used in public transport, but is also in use for cha ...

Products featuring the Apple A4

* iPad (1st generation) *

* iPod Touch (4th generation) *

Apple TV (2nd generation) Apple TV is a digital media player and microconsole developed and marketed by Apple Inc. It is a small network appliance hardware that plays received media data such as video and audio to a television set or external display. Since its seco ...

Gallery

References

External links

MacWorld – Apple inside: the significance of the iPad's A4 chip
* CNET�
Inside the iPad: Apple's new 'A4' chip
* HotHardware�
iPad's Identity Crisis and Apple's A4 CPU Showstopper
* EETimes�
Apple's A4 dissected

Understanding iPad’s A4 Processor

ARM Cortex-A series processors

PowerVR GPU specifications pages
{{Application ARM-based chips Products introduced in 2010 Products and services discontinued in 2014 Apple silicon

Design

Products featuring the Apple A4

Gallery

See also

References

External links