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发帖数: 3838 | 1 http://www.appleinsider.com/articles/11/03/13/inside_apples_ipa
_than_tegra_2.html
The new A5 processor used by iPad 2 incorporates Samsung's new 46nm Low
Power DDR2 memory, uses a
variable clock speed and costs about $25, a significant premium over NVIDIA'
s competing Tegra 2.
According to research performed by UBM TechInsights, Apple's larger A5 (12.
1mmx10.1mm, compared to
the 7.3mmx7.3mm A4) costs about $25 to build, making it $10 more expensive
than similar dual core
chips such as the Tegra 2 used by the Motorola Xoom.
Even so, the firm estimates the iPad 2 total Bill Of Materials costs about $
270, compared to its BOM
estimate of the Xoom, which weighs in at $288 (both numbers compare 32GB 3G
versions).
Cheaper by the million dozen
"To help with their margins," UBM engineer and technical marketing manager
Allan Yogasingam told
AppleInsider, "this basically guarantees the A5 will be in most next
generation Apple products like the
iPhone 5 and the iPod Touch. It will help bring the costs down to the $15
range of their competition -
especially if they have a plan in place to ramp up production through
another fab like TSMC."
Yogasingam noted that despite rumors that Apple may be working with TSMC to
build A5 chips, "the A5 in
our possession is definitely manufactured by Samsung using their 45nm
process."
"Our first inclination that this could be a Samsung manufactured processor
was the similarity in word mark
between this font and the font in the Apple A4," the Yogasingam stated (
below, A4 wordmark is in the inset
image.)
The A5 up close, really close
UBM TechInsights also said it "used optical die and SEM cross-section images
to analyze features such as
die edge seal, metal 1 pitch, logic and SRAM transistor gate measurements.
These features were then
compared to other manufacturers in our database, including other Samsung
45nm parts," indicating that
the A5, like the previous generation Apple A4 processor, was built using
Samsung’s 45nm process.
Yogasingam provided a full scale die photo of the Apple A5 Processor (above)
. A side view image of the A5
processor reveals the package-on-package of the processor and low-power DDR2
DRAM (below).
A SEM (Scanning Electron Microscopy) cross-section image showing the SRAM
transistors in the Apple A5
processor (below).
Evolution of Apple's APL chips
Apple has used a series of Applications Processors in its iPhone, iPod touch
and iPad models since 2007.
Initial versions of the chips were designated as 8900B series, while later
versions were labeled in an APL
series. Only last year did Apple begin naming its processor as "the A4," a
step similar to the company's
previous branding of third, fourth, and fifth generations of PowerPC chips
the G3, G4 and G5.
In addition to much faster graphics based on the dual core SGX543MP2
graphics technology licensed from
Imagination Technologies, the A5 also boasts dual processing cores based on
ARM Cortex A9, with a
dynamically set clock speed.
Dynamic clock, faster RAM
"While the A4 clock speed was steady at 1 GHz," Yogasingam said, "the A5
clock speed varies depending on
the application being run. This would indicate an advanced power management
circuitry controlling the
clock speeds of the cores—something new for the A5 and may explain the use
of a different power
management IC from Dialog Semiconductor."
Also notable in the A5 is the use of fast new Low Power DDR2 DRAM memory. "
What is also interesting is
that teardowns performed at two UBM TechInsights locations (in Austin and
Ottawa) revealed two different
LPDDR2 DRAM from two different manufacturers (Samsung and Elpida). The
Samsung K4P2G324EC LPDDR2
die is the first time we’ve seen Samsung’s new 46nm LPDDR2 memory. This
also tells us that Apple is fully
prepared to package multiple LPDDR2 offerings." |
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