Reply by rickman February 4, 20132013-02-04
On 2/2/2013 6:22 PM, j.m.granville@gmail.com wrote:
> On Tuesday, January 29, 2013 3:51:04 PM UTC+13, rickman wrote: >> I am currently oriented towards absurdly low power levels in digital >> designs and am working on a design that will require no explicit power >> source, it will scavenge power from the environment. I don't think a >> Propeller is suitable for such a task is it? > > Depends on your work-load, and just how much power... > > The Prop is RAM loaded, so avoids the FLASH cost of many cores, and the data shows ~3.5uA @ 3v3 static, but being RAM based it can Vcc scale below that. > (but it does have a boot-energy, which could be another issue..) > > That is likely too high for most "scavenge power", but it also climbs slowly, so it can Poll a pin at 60KHz and ~10uA. > > Some experimental numbers are found by google here > http://forums.parallax.com/showthread.php/133434-Booting-the-Prop-from-low-voltages-2-of-3-Scavenged-Headphone-Audio-0.42V > and > http://forums.parallax.com/showthread.php/133382-Booting-the-Prop-from-low-voltages-1-of-3-Single-Solar-Cell-0.56V > and then also > http://forums.parallax.com/showthread.php/133455-Booting-the-Prop-from-low-voltages-3-of-3-Meyer-Lemon-0.42V > and also > http://forums.parallax.com/showthread.php/129731-Prop-Limbo!-how-low-%28power-voltage%29-can-it-go!
That's very interesting, thanks. -- Rick
Reply by February 2, 20132013-02-02
On Tuesday, January 29, 2013 3:51:04 PM UTC+13, rickman wrote:
> I am currently oriented towards absurdly low power levels in digital > designs and am working on a design that will require no explicit power > source, it will scavenge power from the environment. I don't think a > Propeller is suitable for such a task is it?
Depends on your work-load, and just how much power... The Prop is RAM loaded, so avoids the FLASH cost of many cores, and the data shows ~3.5uA @ 3v3 static, but being RAM based it can Vcc scale below that. (but it does have a boot-energy, which could be another issue..) That is likely too high for most "scavenge power", but it also climbs slowly, so it can Poll a pin at 60KHz and ~10uA. Some experimental numbers are found by google here http://forums.parallax.com/showthread.php/133434-Booting-the-Prop-from-low-voltages-2-of-3-Scavenged-Headphone-Audio-0.42V and http://forums.parallax.com/showthread.php/133382-Booting-the-Prop-from-low-voltages-1-of-3-Single-Solar-Cell-0.56V and then also http://forums.parallax.com/showthread.php/133455-Booting-the-Prop-from-low-voltages-3-of-3-Meyer-Lemon-0.42V and also http://forums.parallax.com/showthread.php/129731-Prop-Limbo!-how-low-%28power-voltage%29-can-it-go!
Reply by Mark Wills January 31, 20132013-01-31
On Jan 31, 6:38&#4294967295;pm, Alex McDonald <b...@rivadpm.com> wrote:
> On Jan 31, 6:57&#4294967295;am, Mark Wills <forthfr...@gmail.com> wrote: > > > > > > > > > > > On Jan 30, 8:18&#4294967295;pm, David Brown <david.br...@removethis.hesbynett.no> > > wrote: > > > > On 30/01/13 13:19, Anders.Monto...@kapsi.spam.stop.fi.invalid wrote: > > > > > In comp.arch.embedded David Brown <da...@westcontrol.removethisbit.com> wrote: > > > > >> Another very useful term is "fangle", which is the Scottish word that > > > >> perfectly describes the organisation of cables on most embedded > > > >> developers' desks. > > > > > Gives a whole new meaning to the phrase "new-fangled". > > > > > -a > > > > This would make more sense if I could spell - normally I rely on > > > Thunderbird's spell checker, but of course that doesn't help here! &#4294967295;I > > > meant to write "fankle" rather than "fangle", and I don't think the > > > terms are related. > > > Fankle was our "Word of the week" here in the office just last week. > > Every week a word is chosen, and it's printed out on A3 and put up on > > the wall. It is every engineers moral obligation to use that word as > > many times as he can in every conversation he engages in. It's > > hilarious. Makes client meetings so much more entertaining. > > Next week's word: stramash.http://www.merriam-webster.com/dictionary/stramash
Fit like, min? Its nae my shot at word of the week next week, but see when it's my shot, Stramash it'll be. Ken?
Reply by Alex McDonald January 31, 20132013-01-31
On Jan 31, 6:57&#4294967295;am, Mark Wills <forthfr...@gmail.com> wrote:
> On Jan 30, 8:18&#4294967295;pm, David Brown <david.br...@removethis.hesbynett.no> > wrote: > > > > > > > > > > > On 30/01/13 13:19, Anders.Monto...@kapsi.spam.stop.fi.invalid wrote: > > > > In comp.arch.embedded David Brown <da...@westcontrol.removethisbit.com> wrote: > > > >> Another very useful term is "fangle", which is the Scottish word that > > >> perfectly describes the organisation of cables on most embedded > > >> developers' desks. > > > > Gives a whole new meaning to the phrase "new-fangled". > > > > -a > > > This would make more sense if I could spell - normally I rely on > > Thunderbird's spell checker, but of course that doesn't help here! &#4294967295;I > > meant to write "fankle" rather than "fangle", and I don't think the > > terms are related. > > Fankle was our "Word of the week" here in the office just last week. > Every week a word is chosen, and it's printed out on A3 and put up on > the wall. It is every engineers moral obligation to use that word as > many times as he can in every conversation he engages in. It's > hilarious. Makes client meetings so much more entertaining.
Next week's word: stramash. http://www.merriam-webster.com/dictionary/stramash
Reply by Mark Wills January 31, 20132013-01-31
On Jan 30, 8:18&#4294967295;pm, David Brown <david.br...@removethis.hesbynett.no>
wrote:
> On 30/01/13 13:19, Anders.Monto...@kapsi.spam.stop.fi.invalid wrote: > > > In comp.arch.embedded David Brown <da...@westcontrol.removethisbit.com> wrote: > > >> Another very useful term is "fangle", which is the Scottish word that > >> perfectly describes the organisation of cables on most embedded > >> developers' desks. > > > Gives a whole new meaning to the phrase "new-fangled". > > > -a > > This would make more sense if I could spell - normally I rely on > Thunderbird's spell checker, but of course that doesn't help here! &#4294967295;I > meant to write "fankle" rather than "fangle", and I don't think the > terms are related.
Fankle was our "Word of the week" here in the office just last week. Every week a word is chosen, and it's printed out on A3 and put up on the wall. It is every engineers moral obligation to use that word as many times as he can in every conversation he engages in. It's hilarious. Makes client meetings so much more entertaining.
Reply by rickman January 30, 20132013-01-30
On 1/29/2013 9:10 PM, None wrote:
> rickman<gnuarm@gmail.com> writes: > > Yes, each cog has its own PLL and "video" bit stream engine (quotes because > they claim it can be used for any sort of analog stream in general). They > needed to use a pair of cogs (CPU's) because of the time it takes to pull > from screen memory as conceived by the ANSI emulation and generate the > scan lines to represent the font plus underline plus cursor. So the idea > is one is doing all that while the other is painting scan lines. Double > buffering, basically.
More like splitting the work load between two processors. I did timing analysis of this (back of the envelope type stuff) for the GA144 and it would be pretty simple with 100's of MIPs per CPU. I wouldn't think it would be that hard with any processor running at reasonable clock rates. Not sure why they need two CPUs. It all depends on the pixel clock rate. For a terminal (what you seem to be describing) the pixel rate should be fairly low, 50-80 MHz. That gives a character rate of 10 MHz max, so I guess that could tax a 100 MIPS processor.
>> Not 100%? What does that mean? Magic? I guess this is the magic smoke >> you want to keep from getting out of the chip? > > Yes, there is no formal/deterministic way to lock the PLL's of the two > cogs. Everybody uses the sample code Parallax provided, and it has > definitely been shown that their "lock" can be skewed.
I don't know what the architecture of this design is. Ideally there would be no need to lock the two processors.
>> I still don't know enough about the architecture to know what this >> means. I don't care if the CPUs are not coordinated closely. If you >> have a video engine providing the clock timing, why would the CPU timing >> matter? > > They have *two* video engines. Each is generated from its own PLL, so > the first global clock is a crystal oscillator.
I have no image of how or why you would want to use *two* video engines, although two could be used with one for the char data and one for the cursor overlay. I also don't know anything about these "video engines". If they are indeed video engines, they should be doing all the addressing and fetching from memory. One way a terminal saves memory bandwidth is by not fetching the same chars again for each line. In an old implementation I remember seeing they used a shift register to recycle the same char data for each scan line.
>> I appreciate your enthusiasm, but I have my own goals and projects. I >> am currently oriented towards absurdly low power levels in digital >> designs and am working on a design that will require no explicit power >> source, it will scavenge power from the environment. I don't think a >> Propeller is suitable for such a task is it? > > Darn, because I'm pretty sure you are much better equipped to drill > down into this than I. :-> But, no way, a Propeller is definitely a > traditional CPU for your purposes.
I'm happy to discuss this with you. Rick
Reply by David Brown January 30, 20132013-01-30
On 30/01/13 13:19, Anders.Montonen@kapsi.spam.stop.fi.invalid wrote:
> In comp.arch.embedded David Brown <david@westcontrol.removethisbit.com> wrote: > >> Another very useful term is "fangle", which is the Scottish word that >> perfectly describes the organisation of cables on most embedded >> developers' desks. > > Gives a whole new meaning to the phrase "new-fangled". > > -a >
This would make more sense if I could spell - normally I rely on Thunderbird's spell checker, but of course that doesn't help here! I meant to write "fankle" rather than "fangle", and I don't think the terms are related.
Reply by January 30, 20132013-01-30
In comp.arch.embedded David Brown <david@westcontrol.removethisbit.com> wrote:

> Another very useful term is "fangle", which is the Scottish word that > perfectly describes the organisation of cables on most embedded > developers' desks.
Gives a whole new meaning to the phrase "new-fangled". -a
Reply by None January 29, 20132013-01-29
rickman <gnuarm@gmail.com> writes:
> Weird, your posts all show up in my reader as replies to your own > messages rather than replies to my posts. The trimming made it hard for > me to figure out just what we were talking about with the odd > connections in my reader.
Sorry. I'm assuming your reader is threading via the "References" field? It looks like my posting software is preserving that.
> > The chip has a lower level bit stream engine which the higher level CPU > > ("cog") is feeding. Well, a pair of cogs. Each cog has local memory > > and then a really expensive path through a central arbiter ("hub"). It > > fills its image of the scanlines from the shared memory, then has to > > feed it via waitvid into the lower level. Note that it's bit stream > > engine *per cog*, so you also have to worry about their sync. > I can't picture the processing with this description. I don't know > about the higher level and lower level CPUs you describe. Are you > saying there is some sort of dedicated hardware in each CPU for video? > Or is this separate from the CPUs? Why a *pair* of COGs? I assume a > COG is the Propeller term for a CPU?
Yes, each cog has its own PLL and "video" bit stream engine (quotes because they claim it can be used for any sort of analog stream in general). They needed to use a pair of cogs (CPU's) because of the time it takes to pull from screen memory as conceived by the ANSI emulation and generate the scan lines to represent the font plus underline plus cursor. So the idea is one is doing all that while the other is painting scan lines. Double buffering, basically.
> Not 100%? What does that mean? Magic? I guess this is the magic smoke > you want to keep from getting out of the chip?
Yes, there is no formal/deterministic way to lock the PLL's of the two cogs. Everybody uses the sample code Parallax provided, and it has definitely been shown that their "lock" can be skewed.
> I still don't know enough about the architecture to know what this > means. I don't care if the CPUs are not coordinated closely. If you > have a video engine providing the clock timing, why would the CPU timing > matter?
They have *two* video engines. Each is generated from its own PLL, so the first global clock is a crystal oscillator.
> > Anyway, you should buy one and check it out. I'd be curious to hear > > if (1) you also observe the same video quality, and (2) if you think it's > > the waitvid mechanism, more the PLL->SVGA generation, or the sync issues > > of the paired video generators. They even supply the schematic, FWIW. > I appreciate your enthusiasm, but I have my own goals and projects. I > am currently oriented towards absurdly low power levels in digital > designs and am working on a design that will require no explicit power > source, it will scavenge power from the environment. I don't think a > Propeller is suitable for such a task is it?
Darn, because I'm pretty sure you are much better equipped to drill down into this than I. :-> But, no way, a Propeller is definitely a traditional CPU for your purposes. Andy Valencia Home page: http://www.vsta.org/andy/ To contact me: http://www.vsta.org/contact/andy.html
Reply by David Brown January 29, 20132013-01-29
On 29/01/13 02:13, Hugh Aguilar wrote:
> On Jan 25, 12:03 am, Mark Wills <forthfr...@gmail.com> wrote: >> On Jan 25, 6:55 am, Hugh Aguilar <hughaguila...@yahoo.com> wrote: >> >>> On Jan 24, 3:03 pm, Mark Wills <markrobertwi...@yahoo.co.uk> wrote: >> >>>> The TMS99xx family of processors (very old) has 16 prioritised >>>> cascading interrupts. Probably inherited from mini-computer >>>> architecture. Very very powerful for its day. Since they were >>>> prioritised, a lower level interrupt would not interrupt a higher >>>> level interrupt until the higher level ISR terminated. Makes serving >>>> multiple interrupts an absolute doddle. Not bad for 1976. >> >>> Doddle? I've never heard that word before. Is a doddle good or bad? >> >> doddle = extremely simple/easy >> >> "Did you manage to fix that bug?" >> "Yeah, it was a doddle!" >> >> :-) > > Maybe the reason why we don't have "doddle" or any similar word in > America, is because we never do anything the simple/easy way here! :-) >
I am not sure, but I think "doddle" is perhaps a Scottish term. As far as I could tell from an online dictionary, the origins are from the German word for bagpipe... Another very useful term is "fangle", which is the Scottish word that perfectly describes the organisation of cables on most embedded developers' desks.