Intel has officially named its processor for smartphones, claiming to have cured excessive stand-by current drawn by first generation Atoms.
"This is a product designed for smartphones. The performance we get from this design will scale up into tablets," said Intel sales director Rod O'Shea.
Previously nicknamed Moorestown, these 45nm smartphone products have been dubbed the Z6xx series.
As second-generation Atoms, they join the recently released Pine Trail processors for netbooks as a lower power lower performance cousin.
Several techniques have been used to saved power compared with the earlier 45nm Z5xx phone processor series, said Intel fellow and Moorestown architect Ticky Thakkar.
One has been a move to a fab process that allows slower, less power hungry, transistors to be used in non-critical circuit blocks.
Another is widely implementing power-gating as well as clock-gating across 19 power islands.
To exploit power gating, there are changes to the operating system and a new lowest-power hardware stand-by state called S3 which supplements the existing S1 idle state.
S3 power dissipation is claimed to be 100µW.
Intel will not yet reveal the equivalent figure for S1.
In a presentation at the launch, a 20x improvement in power consumption for audio playback was claimed compared with earlier Atoms, probably through the use of low power transistors in the MP20 companion chip - see below - and a 2-3x improvement for video and browsing.
To save power, the firm expects the processor to be switching from full power to stand-by or idle many times a second.
Thakkar made much of the speed at which the chip can mode switch. "Nought to 1.5 or 1.9GHz in microseconds," he said.
Intel latency figures are 400[micro]s entering SOi3 and 3.1ms leaving, with 600[micro]s and 1.2ms respectively for SOi1.
Around the core is 24kbyte data cache, 32kbyte instruction cache, and 512k of L2 cache.
Alongside this on the silicon is a graphics engine from Imagination Technology and a video decode-encode engine, as well as memory and display controllers.
Thakkar told Electronics Weekly that, unusually for smartphone processors, the video accelerator has been sized for 1080p playback: "Over 20Mbit/s frame rate," he said.
This extra capability has added a power burden at lower speeds, putting it at the top end of power consumption for smartphone 720p playback.
Other functions are mopped up in the 65nm MP20 companion 'controller hub' chip.
This includes USB and HDMI I/O to output video, a solid-state drive interface, a 32bit RISC system controller, a crypto cell, audio acceleration, and a camera interface.
There is also Briertown, and Intel-specified mixed signal chip that absorbs analogue system functions including battery charging and voltage regulation.
Firms including Freescale, Maxim and Renesas will be making Briertown chips, according to Intel.
Pankaj Kedia, director of mobile devices at Intel, said stand-by power consumption of a mobile device using an old atom was 1.2W, compared with 21mW from a mobile device based around Z6xx, MP20, and Briertown; adding: "audio playback takes only 120mW."
Intel's claimed run-times for a Moorestown phone with a 1.5Ah battery are: 10day stand-by, 2day audio playback, 5hour 720p play, 4hour 1080p play, 5h browsing, and 6h 3G talk time.