NEC breakthrough paves way for powerless standy-by modes
NEC has announced the development of a memory circuit element that, it claims, will allow chips to consume no power when they're put in stand-by mode.
The circuit component is a non-volatile magnetic flip-flop (MFF) - not a reference to cheap footwear but to a transistor-based circuit of the type assembled by schoolboys to make two lightbulbs flash alternately.
In processors, the circuit is used as the basis of a 1-bit memory cell, storing a bit in its two possible states, within the register storage space.
Existing flip-flops require power to maintain their state and a clock circuit to control them. NEC's MFF uses magnetism to eliminate the need for juice.
So, says NEC, use MFFs instead of traditional memory flip-flops and non-volatile MRam cells instead of SRam, and you have the basis for a system-on-a-chip part that can be completely powered down yet still retain data - something traditional SoCs can't do.
Using MRam, the company added, also gets over the limited write life of Flash chips - MRams have "unlimited write endurance", NEC said.
NEC said it has made a working MFF that can operate at 1.2V or less - the same voltage range as standard SoC flip-flops - and at clock speeds of up to 3.5GHz. By working to these parameters, NEC said, it should be easy to integrate the new flip-flop structure into existing chip circuit designs. ®
Powerless Standby Modes.and non-volatile Memory
Surely no only I remember CORE MEMORY ??
We used to power down NAVDAC in 1966, and on Power-Up, the core memory remembered everything it had when powered down. Of course, it was a serial, NAND gate based, discrete component computer, maintained to component level ! VERY old !
MARDAN on the other hand had RECIRCULATING REGISTERS on the HDD. They too could be made to hold unchanged content through a power-down. Same generation of computer, though.
A bit like, but simpler than writing memory to a boot- like sector on the HDD (Perhaps the one after the boot sector).
I thought Laptops already did this ??
I see the children are re-inventing the wheel again !!
I think what you're all missing here is...
In "traditional" computer memory, each bit has to be topped up with charge every so often in order to retain what it stores. If this magnetised memory doesn't need this then it will save power even when the device is on. Just because the memory has no power running through it doesn't make it unusable - the memory controller being on/off defines that.
What this means is that, yes, your phone in standby (what I think you meant here was sitting idle in your pocket, which is not what the article is refering to, if I'm correct) can receive a call because the GSM modem (is that the right term? I'm no telecoms expert) will still have power running through it and can send interrupts just the same when a call arrives.
Whist this doesn't mean great things for battery life of a computer whilst it is on (as was rightly said, the screen takes most of that) the battery life of the computer won't discharge whilst it is in standby mode (mine takes about a day to go flat like this, so useful if you accidentally leave it on overnight). Also, whilst it may not be a great saving of power for your single computer, think about how many computers there are out there and if they are all slowly replaced by computers that don't have to "top up" the charge in their memory every few nanoseconds then THAT will be a considerable saving.
@ Steve Jones
The issue with Flash is that the write cycle is too slow for use as Regular memory.
It sounds like this memory is going to be fast enough to use as Regular computer memory so Standby mode will not need to power the memory and as the Greenies say 'a milliwatt-hour saved is one less picogram of CO2 in the atmosphere'....
No seriously - the less that needs to be powered up when a computer is in standby the smaller the battery that is needed and think about being able to turn your computer on and not having to wait interminably for it to boot up (because it is still booted up).
You obviously don't recollect your schooldays so well!
> flip-flop ... a transistor-based circuit of the type assembled by schoolboys to make two
> lightbulbs flash alternately
No! A flip flop is a simple (bi-stable) memory device, which can store 1 bit of information. To make it oscillate automatically, you must add two capacitors. Then you have an astable multivibrator.
As in Tellybox Flash?
SoC's (apologies for the redundant apostrophe but ...) rapid on/off/standby tellyboxes?