Rick Lyons wrote:> On Thu, 08 Dec 2005 02:47:53 GMT, Randy Yates <yates@ieee.org> wrote: > > (snipped) > >>>What would be interesting to me is if Vladimir could tell >>>us the following: if continous binary adds require P watts >>>in a DSP chip, do continuous multiplies requre 2P, 4P, >>>8P watts, or what. >> >>Hi Rick, >> >>TI has a spreadsheet for this for the DM64x DSP, so you can play with >>the numbers there: >> >>http://focus.ti.com/docs/apps/catalog/resources/appnoteabstract.jhtml?abstractName=spra962f >> >>The spreadsheet inputs (for the CPU) are percent CPU utilization and >>clock frequency, so you can't really compare adds to MACs, for >>example. They also use some sort of non-linear relationship (as a >>function of percent utilization), but it's close to linear. >> >>Power consumption estimation on a chip like this, which is really a >>group of complex subsystems, and in which the subsystems interact, >>is no easy task. >>-- >>% Randy Yates % "Bird, on the wing, > > > Hi Randy, > Thanks, I'll have a look.I've heard of using the power vs. time curve as clues to reverse engineering. Good encryption algorithms maintain a "power drain poker face" while doing there thing. It's too easy to break the code if they don't. Jerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������
symmetric transpose form fir filter
Started by ●November 30, 2005
Reply by ●December 8, 20052005-12-08
Reply by ●December 9, 20052005-12-09
Jerry Avins wrote:> Rick Lyons wrote: > >> On Thu, 08 Dec 2005 02:47:53 GMT, Randy Yates <yates@ieee.org> wrote: >> >> (snipped) >> >>>> What would be interesting to me is if Vladimir could tell us the >>>> following: if continous binary adds require P watts >>>> in a DSP chip, do continuous multiplies requre 2P, 4P, 8P watts, or >>>> what. >>> >>> >>> Hi Rick, >>> >>> TI has a spreadsheet for this for the DM64x DSP, so you can play with >>> the numbers there: >>> >>> http://focus.ti.com/docs/apps/catalog/resources/appnoteabstract.jhtml?abstractName=spra962f >>> >>> >>> The spreadsheet inputs (for the CPU) are percent CPU utilization and >>> clock frequency, so you can't really compare adds to MACs, for >>> example. They also use some sort of non-linear relationship (as a >>> function of percent utilization), but it's close to linear. >>> >>> Power consumption estimation on a chip like this, which is really a >>> group of complex subsystems, and in which the subsystems interact, >>> is no easy task. >>> -- >>> % Randy Yates % "Bird, on the wing, >> >> >> >> Hi Randy, >> Thanks, I'll have a look. > > > I've heard of using the power vs. time curve as clues to reverse > engineering. Good encryption algorithms maintain a "power drain poker > face" while doing there thing. It's too easy to break the code if they > don't. > > Jerrytheir thing, dammit! -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������
Reply by ●December 9, 20052005-12-09
Steve Underwood <steveu@dis.org> writes in some detailed about interesting power reduction techniques:> [...]We never tweaked at this level in our handset code at Ericsson/Sony Ericsson, but thanks for the ideas, Steve. I guess if you were really going whole-hog for the lowest power they could be very important. Can you tell us what applications you have applied these techniques to? -- % Randy Yates % "Rollin' and riding and slippin' and %% Fuquay-Varina, NC % sliding, it's magic." %%% 919-577-9882 % %%%% <yates@ieee.org> % 'Living' Thing', *A New World Record*, ELO http://home.earthlink.net/~yatescr
