Single-Source PIC, AVR & Alternatives

Banking for 'new process' to deliver hoped for lower powers may be optimistic. {vaporware can promise anything, it's real silicon that counts )

New process has not done this on FPGA, and if one looks at the newest

200Mhz process devices from Atmel, you see these comments :

" The AT91SAM9263 consumes about 700 uA of static current on VDDCORE at

25'C. This static current rises at up to 7 mA if the temperature increases to 85'C. On VDDBU, the current does not exceed 3 uA @25'C, but can rise at up to 20 uA @85'C. A software-controllable switch to VDDCORE guarantees zero power consumption on the battery when the system is on. For dynamic power consumption, the AT91SAM9263 consumes a maximum of 70 mA on VDDCORE at maximum conditions (1.2V, 25°C, processor running full-performance algorithm)."

Depends on your targets, but 700uA-7mA static are not leaps down in Icc in most designer's yardsticks (well, maybe if you come from a PC background ?! :) It does not matter HOW fancy your core is, or how fancy your clock gating, this static Icc is always there, until you remove the power entirely. [This is why dual processor solutions are appearing, and why fewer are expecting one chip to be the final solution ]

Marketing is still driven by MHz first, power 2nd (tho power is certainly now on the radar), and simple maths and physics are still there...

Maybe this will be the solution, for those who still think in uA ?

?articleID=196602004

-jg

I guess that, if the rumour mill is true, that would be me :-)

--
Best Regards,
Ulf Samuelsson
This is intended to be my personal opinion which may,
or may not be shared by my employer Atmel Nordic AB

The Picopower has a power curve that starts at close to zero and increases in almost a linear fashion. The main advantage of Picopower is when you are in sleep mode or are running at low clock frequencies. When running at high frequency, the main benefit is from the new cell library, which is not present in the ATmega128, that Rickman compares with.

--
Best Regards,
Ulf Samuelsson
This is intended to be my personal opinion which may,
or may not be shared by my employer Atmel Nordic AB

No, I haven't seen any comments from you on xmega, unless you are using different user names on different sites

I think Ulf was answering (strictly) the question "Who knows what features they will have ?"

- hence the smiley...

a better question would be "who is prepared to say what features they will have?" - if the rumour is true, of course.

Seems there is always something new in the pipeline....

-jg

Microchip has been good with old parts. Find some old numbers and hit them into Digi-key. Plus a lot of there parts migrate upward. a 28pin part is always pin compatible with other parts. Handy if you need more features or power later.

I guess, if the rumour mill is true, that would not be me ;-)

--
Best Regards,
Ulf Samuelsson
This is intended to be my personal opinion which may,
or may not be shared by my employer Atmel Nordic AB

I looked at the data sheet for the pico power part you recommended, the ATmega324P. It does not seem to be significantly better than the ATmega128. It draws 7.4 mA at 8 MHz which is 37 mW at the rated 5 volt power. It draws 2.1 mA at 4 MHz and 0.4 mA at 1 MHz. This is essentially the same (or worse) as the SAM7S parts, no? The price listed in the press release is not any better than SAM7 prices.

As much as you wave your arms, I have not seen any information that shows that either the SAM7 or the AVR devices will do a good job of competing against the CM3 devices coming out in 2007. I understand that with limited resources it may not be the best idea for Atmel to develop a CM3 device line at this time. But I think it is pretty clear that the CM3 is the way that ARM designs will be headed in the near future and that the days of the ARM7 are numbered.

" ... and that the days of the ARM7 are numbered". That's exactly why some things such as the 8051 are so successful in the marketplace. Large parts of the industry (including pretty much all of my clients) cannot consider any components that are likely to fall from grace within a few years.

--
Regards, Joerg

http://www.analogconsultants.com

Check out AD 'analog ARM's from the ADuC7xxx series:

$5 40MHz 8kB SRAM/62kB Flash, 10 ADC, 4 DAC, analog and digital inputs 5V-tolerant, PWM/timers/I2C/serial, 50 uA sleep, 50 mA running. They have a nice ADUC7020 Miniboard eval kit for $30, which is in a 40-pin DIL form factor---looks ideal for prototyping:

There's a lot of choice in the ARM space, and as a result nice leapfrogging---the customer wins.

Disclaimer: I have no connection to ARM or AD---just read about their new stuff.

I can bitch about their instruction set all day, but that pin compatibility is sure sweet.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Posting from Google?  See http://cfaj.freeshell.org/google/

"Applied Control Theory for Embedded Systems" came out in April.
See details at http://www.wescottdesign.com/actfes/actfes.html

The Hi-tech compiler generates Very reasonable sized Code. I just ignore it. It is still 8 bits of course.

I have used that chip, at full speed the power/mips ratio is great, but at 1Mhz, the typical power requirement is 40X greater the MSP430/AVR, at 300Khz, 100X greater, and that is with no A/D's or DAC running

I have looked at the ADUC ARM stuff and it is a nice chip if you need good analog. But it has a 7 mA quiescent power draw. I was just at a seminar for these parts and they confirmed that this is true, but did not give an explanation for it.

Like you say, at full power it is ok, but if you are trying to save power by running a slow clock it is not a good choice.

7mA has got to be a design error (I mean, it's not like a Pentium with 65nm transistors that leak like sieves...), so I'd expect they'd come out with a better version ASAP.

I'm sure someone's butt has been roundly kicked...

I don't think it is that simple. These devices have been out for well over a year and I don't think they have any intention of respinning them. I would speculate that the precision analog has something to do with the high quiescent draw, but I am not a chip design expert, so I can't really say.

don't know, but I was following the ADUC ARM's since the first preliminary datasheets were released (a few years ago), the low speed power draw was much lower back then, but on the final datasheet it jumped up to 7mA typical, 10mA max

Some of Maxims MAXQ's are similar.

There are two main current hogs: FLASH memory, and Analog cells. Some devices leave the FLASH charge pumps/sense amps enabled, which gives faster speeds, but has a static Icc cost.

Most wake up Flash as they need it, but that has a time-cost, so your MIPS are lower than they could be.

Analog cells can be powered on/off, sometimes that can be simply overlooked.

Or, they might find that the impedance of the Vcc switch adds too much impedance/noise to meet the important Analog targets, so they do a metal layer change and short it out.

-jg

The ADUC flash is unusual in that a page can be erased (or reprogrammed) during code execution from another page. This is extremely useful (and not mentioned in the datasheet). It makes the interbal flash ideal for keeping user settings or data logging, replacing e.g. an external EEPROM. Other micros I have used require you to execute the programming code from RAM & turn off interrupts.

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John Devereux