The video is amazing... Although the woman comes to completely the wrong conclusion - all these methods are valuable. Children (no scratch that... people) who see the equivalence of all these methods are much more likely to be able to apply them in appropriate situations and really understand what they are doing.
Without a piece of paper, adding partial products is difficult - so for quick sums, the reasoning technique (breaking 26x into the sum of 20x , 2x and 1x) lends itself well to approximation, which helps in quick decision making.
I'd never seen the lattice method taught in school-maths but was extremely suprised to see her assert that people can't explain why it works? It's an array multiplier - 'My-First-Multiplication-Circuit' from digital hardware design 101.
The question of selecting an appropriate multiplication algorithm is obvious in hardware design since we have clear metrics of power, performance and area to evaluate it against.
Perhaps a better explanation of multiplication methods to children could be derived if we examined them in a framework which explicitly considered them in terms of verbosity, speed and correctness.
Whether or not the phone is "really" running OSX is debatable, but keep in mind that many of the CPUs used in embedded devices like phones don't have nearly (or sometimes any of) the memory protection offered on a desktop or laptop CPU. You're also dealing with a much lower-MHz device (for battery consumption reasons) and chances are 100% of the code on the phone runs in Ring 0 (assuming other rings exist) for performance reasons.
So for them to allow third parties to run binary apps would pretty much allow unlimited circumvention of their DRM for the iPod portions (which would violate their agreements with record and movie companies)
For the kind of applications processors used (ARM926, ARM1136/1176, Cortex A8) in smartphones - the MMU implementation is much more sophisticated than what is available in my x86 laptop, what is more, the level of fine grained control over TLB/Cache invalidation means higher performance and better energy-efficiency. The 'Trustzone' features marketed by ARM give you a 'processor-within-a-processor' features with complete isolation of secure and non-secure code all the way through the level-1 memory system to bus-based peripherals. This is the reason such processors are trusted for 'virtual wallet' applications.
So the technology is more than sufficient to implement all the isolation necessary. The likely reason for not giving developers full control over third party apps is that many of the iPhones most innovative features are based around 'network service'device integration (like visual voicemail) , and that a whole bevy of applications are in the pipeline to increase ARPU to AT&T, and other operators across the world.
You appear to be under the misapprehension that VLSI designs are planar graphs. The place and route tools used to move from RTL to GDSII layouts make assumptions (depending upon the manufacturing process) of anywhere between 4 and 20 metal layers.
The technology described in the article is exciting but not novel... academics has been exploring memory hierachies, hardware dynamic thread scheduling, and introspective debug solutions for some years.
For reference... Last years ASPLOS (06) conference includes 2 papers with disruptive 3D stacking technologies.
PICOSERVER: USING 3D STACKING TECHNOLOGY TO ENABLE A COMPACT ENERGY EFFICIENT CHIP MULTIPROCESSOR.
Joint paper between Univ. of Mich. and ARM which shows how 3D stacking of DRAM dies (which have difference process req. to logic)on top of logic can radically reduce power, increase memory bandwidth and save area (since L2 cache becomes unnecessary)
INTROSPECTIVE 3D CHIPS.
UC Santa Barbara group show that 3D stacking allows the inclusion of a host of dynamic debug features which allow monitoring of the processor pipeline - without adding cost to the production version of the chip.
So... not just cool, super cool, but fundamental challenges remain, chiefly - can we achieve reliable interconnects between thousands of die-to-die vias (with the implication that if you bugger it up, both dies are useless), secondly, can we develop better wafer level testing so we don't end up going through the expensive stacking process with duff dies. Thirdly, better tools for modelling heat dissipation in such stacks is needed if they are going to be reliable in every-day use.
It's really important to make a distinction between ARM Ltd- who make IP cores implementing the ARM architecture (now at version 7) and XScale which is an Intel implementation of the ARM v4/v5 architecture. Intel has an architecture license to produce products compatible with ARM-derived cores. Any kind of micro-architectural vulnerability is very unlikely to be shared across ARM Ltd and Intel implementations because they share no heritage. So making sweeping statements of vulnerabilities across all ARM-compatible embedded devices is premature and unnecessary
David... Your comment is especially insightful. I wish I had some mod-points to pull it out of the melee of useless posturing written here!
I've been thinking about a review of patents on my own particular area of electronic engineering (FPGA design) with the goal of setting out exactly where the challenges to an open-source solution lie.
The biggest concern to me is not the size of the task - but the fact that US law, if a legal battle can prove the 'wilful and intentional' infridgement of patents, the court will automatically apply triple damages. This means that in certain cases, ignorance is bliss! A comprehensive review of Microsoft's patents would open future Linux developers to greater risk of facing these enhanced penalties (and lets not pretend there aren't some pretty silly patents out there'). This certainly deters me from starting my patent review project.
Can anyone think of an appropriate 'Chinese Wall' style approach which would not destroy deniability? Of course the more militant Linux enthusiasts might do a great deal of social good by fighting the necessary legal battles to invalidate some of the world's more frivolous patents - but it wouldn't be cheap.
Any kind of integration tends to improve power efficiency just because of the high capacitance of the PCB traces. This makes it difficult to route a PCB for high-speed inter-chip communications never mind getting multiple 2.5Gb/s (PCIe) signal traces through a connector. All this requires large driver cells to drive off-chip communication and these use a great deal of power (and moderate area) on chip. Reducing the noise floor of your signals (by keeping them on chip) also gives you more headroom for voltage reductions in your digital hardware. All in all it makes it a much better picture overall for power efficiency. But dissipating power from these new chips will still be a headache for CPU package designers and systems guys alike.
I'm a British Citizen, I'm always appalled at the immigration procedures whenever I enter the US - Last time I entered the US at Philadelphia - I was pulled asideby an immigration officer and interogated (briefly) - his question 'Why are you back so soon' (I'd made 2 trips to US in a month). Tourists to the US are ill-prepared for the sort of treatment they get when entering the US (Which is extremely poor).Poor treatment by rude immigration staff is universal whether you enter by Air/Sea or road (and I've done all of the above) and where-ever you go in the US.
BUT... on every occasion you enter the US under visa-waiver program - you are asked to give the address of where you are staying - this has been asked since way,way before the New York Terrorist attacks in Sept 2001. I don't think it is unreasonable.
A recent post on the US Embassy Website in the UK (http://www.usembassy.org.uk/cons_web/acs/passport s/dualpass1204.htm) shows that US citizens who travel the US MUST travel on their US passports, even if they hold dual-citizenship with another country. This guy was lucky they even let him board the plane - I'm pretty sure it was a favour extended to him because he held 'platinum' status. So... there is no story except... 'man breaks rules - nearly gets away with it - is indignant when he is caught.'
The rules may be arbitrary and stupid (and hey... US citizens at least had a say in electing the people who forced them through) but you can't blame the airlines or immigration staff for enforcing them.
McDonalds is pretty universally popular as fast food whilst shopping etc in UK as far as my perspective. But this is not true across all of Europe. Didn't see a single McDonalds in portugal whilst travelling, nor in Lapland come to think of it.
SO either these people have better taste. Or McDonalds doesn't go where it can sell its particular brand of cheap food
Re:get a Ericsson T68 instead.. - has 1900 too
on
New Nokia Phone
·
· Score: 1
Uh... Because this is a phone for the European Market, and no european network is 1900Mhz.
1900Mhz is just a Nobbled GSM standard to provide a barrier to entry to the US market for European phone manufacturers.
So... In answer to your question. The answer is that Nokia can release a phone with 1900 because the US is not the centre of the world! (SHOCK!)
Slashdot Mirror
The video is amazing... Although the woman comes to completely the wrong conclusion - all these methods are valuable. Children (no scratch that... people) who see the equivalence of all these methods are much more likely to be able to apply them in appropriate situations and really understand what they are doing.
Without a piece of paper, adding partial products is difficult - so for quick sums, the reasoning technique (breaking 26x into the sum of 20x , 2x and 1x) lends itself well to approximation, which helps in quick decision making.
I'd never seen the lattice method taught in school-maths but was extremely suprised to see her assert that people can't explain why it works? It's an array multiplier - 'My-First-Multiplication-Circuit' from digital hardware design 101.
The question of selecting an appropriate multiplication algorithm is obvious in hardware design since we have clear metrics of power, performance and area to evaluate it against.
Perhaps a better explanation of multiplication methods to children could be derived if we examined them in a framework which explicitly considered them in terms of verbosity, speed and correctness.
For the kind of applications processors used (ARM926, ARM1136/1176, Cortex A8) in smartphones - the MMU implementation is much more sophisticated than what is available in my x86 laptop, what is more, the level of fine grained control over TLB/Cache invalidation means higher performance and better energy-efficiency. The 'Trustzone' features marketed by ARM give you a 'processor-within-a-processor' features with complete isolation of secure and non-secure code all the way through the level-1 memory system to bus-based peripherals. This is the reason such processors are trusted for 'virtual wallet' applications.
So the technology is more than sufficient to implement all the isolation necessary. The likely reason for not giving developers full control over third party apps is that many of the iPhones most innovative features are based around 'network service'device integration (like visual voicemail) , and that a whole bevy of applications are in the pipeline to increase ARPU to AT&T, and other operators across the world.
You appear to be under the misapprehension that VLSI designs are planar graphs. The place and route tools used to move from RTL to GDSII layouts make assumptions (depending upon the manufacturing process) of anywhere between 4 and 20 metal layers.
The technology described in the article is exciting but not novel... academics has been exploring memory hierachies, hardware dynamic thread scheduling, and introspective debug solutions for some years.
For reference... Last years ASPLOS (06) conference includes 2 papers with disruptive 3D stacking technologies.
PICOSERVER: USING 3D STACKING TECHNOLOGY TO ENABLE A COMPACT ENERGY EFFICIENT CHIP MULTIPROCESSOR.
Joint paper between Univ. of Mich. and ARM which shows how 3D stacking of DRAM dies (which have difference process req. to logic)on top of logic can radically reduce power, increase memory bandwidth and save area (since L2 cache becomes unnecessary)
INTROSPECTIVE 3D CHIPS.
UC Santa Barbara group show that 3D stacking allows the inclusion of a host of dynamic debug features which allow monitoring of the processor pipeline - without adding cost to the production version of the chip.
So... not just cool, super cool , but fundamental challenges remain, chiefly - can we achieve reliable interconnects between thousands of die-to-die vias (with the implication that if you bugger it up, both dies are useless), secondly, can we develop better wafer level testing so we don't end up going through the expensive stacking process with duff dies. Thirdly, better tools for modelling heat dissipation in such stacks is needed if they are going to be reliable in every-day use.
Kind RegardsIt's really important to make a distinction between ARM Ltd- who make IP cores implementing the ARM architecture (now at version 7) and XScale which is an Intel implementation of the ARM v4/v5 architecture. Intel has an architecture license to produce products compatible with ARM-derived cores. Any kind of micro-architectural vulnerability is very unlikely to be shared across ARM Ltd and Intel implementations because they share no heritage. So making sweeping statements of vulnerabilities across all ARM-compatible embedded devices is premature and unnecessary
David... Your comment is especially insightful. I wish I had some mod-points to pull it out of the melee of useless posturing written here!
I've been thinking about a review of patents on my own particular area of electronic engineering (FPGA design) with the goal of setting out exactly where the challenges to an open-source solution lie.
The biggest concern to me is not the size of the task - but the fact that US law, if a legal battle can prove the 'wilful and intentional' infridgement of patents, the court will automatically apply triple damages. This means that in certain cases, ignorance is bliss! A comprehensive review of Microsoft's patents would open future Linux developers to greater risk of facing these enhanced penalties (and lets not pretend there aren't some pretty silly patents out there'). This certainly deters me from starting my patent review project.
Can anyone think of an appropriate 'Chinese Wall' style approach which would not destroy deniability? Of course the more militant Linux enthusiasts might do a great deal of social good by fighting the necessary legal battles to invalidate some of the world's more frivolous patents - but it wouldn't be cheap.
Regards
Sam Bayliss
Any kind of integration tends to improve power efficiency just because of the high capacitance of the PCB traces. This makes it difficult to route a PCB for high-speed inter-chip communications never mind getting multiple 2.5Gb/s (PCIe) signal traces through a connector. All this requires large driver cells to drive off-chip communication and these use a great deal of power (and moderate area) on chip. Reducing the noise floor of your signals (by keeping them on chip) also gives you more headroom for voltage reductions in your digital hardware. All in all it makes it a much better picture overall for power efficiency. But dissipating power from these new chips will still be a headache for CPU package designers and systems guys alike.
I'm a British Citizen, I'm always appalled at the immigration procedures whenever I enter the US - Last time I entered the US at Philadelphia - I was pulled asideby an immigration officer and interogated (briefly) - his question 'Why are you back so soon' (I'd made 2 trips to US in a month). Tourists to the US are ill-prepared for the sort of treatment they get when entering the US (Which is extremely poor).Poor treatment by rude immigration staff is universal whether you enter by Air/Sea or road (and I've done all of the above) and where-ever you go in the US.
BUT... on every occasion you enter the US under visa-waiver program - you are asked to give the address of where you are staying - this has been asked since way,way before the New York Terrorist attacks in Sept 2001. I don't think it is unreasonable.
A recent post on the US Embassy Website in the UK (http://www.usembassy.org.uk/cons_web/acs/passport s/dualpass1204.htm) shows that US citizens who travel the US MUST travel on their US passports, even if they hold dual-citizenship with another country. This guy was lucky they even let him board the plane - I'm pretty sure it was a favour extended to him because he held 'platinum' status. So... there is no story except... 'man breaks rules - nearly gets away with it - is indignant when he is caught.'
The rules may be arbitrary and stupid (and hey... US citizens at least had a say in electing the people who forced them through) but you can't blame the airlines or immigration staff for enforcing them.
RWE Powerline have been offering 2Mbit/s down your powerline in certain areas of Germany for the best part of a year. Damn good idea!
McDonalds is pretty universally popular as fast food whilst shopping etc in UK as far as my perspective. But this is not true across all of Europe. Didn't see a single McDonalds in portugal whilst travelling, nor in Lapland come to think of it.
SO either these people have better taste. Or McDonalds doesn't go where it can sell its particular brand of cheap food
Uh... Because this is a phone for the European Market, and no european network is 1900Mhz.
1900Mhz is just a Nobbled GSM standard to provide a barrier to entry to the US market for European phone manufacturers.
So... In answer to your question. The answer is that Nokia can release a phone with 1900 because the US is not the centre of the world! (SHOCK!)
I suggest to you that US Policy looks very different to Americans than to Europeans
Arrogant Yank!
While you're busy being protectionist and introverted, the rest of the world is existing beyond your sphere of vision.
I would of thought that the extremist bombing of the WTC would have taught some of you that you can't go on with this attitude.