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,
fourth-generation iPod Touch, and
second-generation Apple TV.
The last operating system update Apple provided for a mobile device containing an A4 (
iPhone 4) 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 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, a ...
(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
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 ...
.
The resulting CPU, dubbed "
Hummingbird", 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, m ...
(GPU). The die of the A4 takes up 53.3 mm² of area.
The
clock rate 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
iPhone 4 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'' ( ...
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.
Products featuring the Apple A4
*
iPad (1st generation)
*
iPhone 4
*
iPod Touch (4th generation)
The fourth generation iPod Touch (marketed as "the new iPod touch", and colloquially known as the iPod Touch 4G, iPod Touch 4, or iPod 4) is a multi-touch mobile device designed and marketed by Apple Inc. with a touchscreen-based user interfac ...
*
Apple TV (2nd generation)
Gallery
See also
*
Apple silicon, the range of ARM-based SoCs designed by Apple.
*
PWRficient
PWRficient is a microprocessor series by P.A. Semi where the PA6T-1682M was the only one that became an actual product.
PWRficient processors comply with the 64-bit Power ISA, and are designed for high performance and extreme power efficiency. T ...
, a series of microprocessors designed by
P.A. Semi. Apple acquired P.A. Semi to form an in-house custom chip design department.
References
External links
MacWorld – Apple inside: the significance of the iPad's A4 chip*
CNET
''CNET'' (short for "Computer Network") is an American media website that publishes reviews, news, articles, blogs, podcasts, and videos on technology and consumer electronics globally. ''CNET'' originally produced content for radio and televi ...
�
Inside the iPad: Apple's new 'A4' chip
* HotHardware�
iPad's Identity Crisis and Apple's A4 CPU Showstopper* EETimes�
Apple's A4 dissectedUnderstanding iPad’s A4 ProcessorARM Cortex-A series processorsPowerVR GPU specifications pages
{{Application ARM-based chips
Products introduced in 2010
Products and services discontinued in 2014
Apple silicon