Stellaris cortex-M3 Power consumpsion

comprasion cortex m3

Hi

Do any one have info about the cortex-M3 Stellaris Power consumpsion?
any comparison for Power consumption with LPC21xx ARM7TDMI based?

Salam
Hossam Alzomor

stellaris cortex-m3 power consumption

You need to be more specific, which particular member of the Stellaris family and which one of the LPC21xx family.
While the core M3 might use less power than the ARM7, there are so many other criteria that have a significant impact on the power consumption. One is the process the devices are manufactured in. Stellaris devices use an older, larger geometry process than the LPC2000 devices, that results in higher power consumption running at the same frequency but an older process provides better standby currents in power down.
Depending what you want to do, an M3 core can provide a better performance, e.g. if you create algorithms with lots of divide instructions, which are not available for the ARM7. In such a case, you can run slower with an M3 performing the same task ask with a faster ARM7.
Most important however is how the connection to the peripherals is done. If many peripherals are clocked all the time, the power consumption will be a lot higher.

In my past, my company did a few measurements using an LPC2103 and a low end Stellaris device. Running the same clock, the LPC came out a lot lower but we did not use the M3 extensions, so the comparison is not apple to apple.
IMHO, Luminary can and will improve the power schemes on the Stellaris family while NXP will introduce more and more LPC1700 devices http://www.lpc2000.com/m3/ (M3 based).
At that time, your question will become void, today it might be a valid question though.

Bob

power consumption of a stellaris m3

Hi,

Thanks Bobsanjoes,

as I understood Based on Arm Documentation Cortex-M3 is a building of ARM7TDMI from scratch again to improve performance and power consumption.
this is for the core.

I understood that the fabrication process will affect max clock and power consumption.

for particuler part I am comparing LPC2103 and LM3S808 , LM3S608
and LM3s1138

in the datasheets for LM3S808 I found that the lowest consumed current during the lowest power mode is 950uA Typical and 1150 uA max. which is very high compared to LPC2103 which claims 10uA in the lowest power mode.


Best Regards
Hossam Alzomor

lm3s608 vs stm32f103

Hello Hossam,

please check what is still running when the LPC2103 uses 10 uAs and the LM3 uses 950 uAs, e.g. whether the Real-Time-Clock still runs. By the way,

I was not aware that the LM3xx is this high in a low power mode. Is you environment subject to high temperature? If so, the LPC2103 can suddenly consume 100 uAs or more if it approaches the 85C. There is less difference for the LM3 because the process is not as temperature dependent.

May be you should also have a look at the STM32 devices e.g. STM32F103, it is similar and has nice low power modes.

Best regards, Bob

lpc1700 stm32 comparison

HI

The LPC21xx and LM3S808 are manufactured using different silicon process.

The LMS produced using 250nM process and consum more power in comper to the LPC21xx

Whether power consumption is the main issue - use the STM32xxx

All the best

Bobi

stellaris power consumption

Hi,

Power consuption is one of the main issues, but price, features and support are main issues too.

How do you compare them from this point of view?

Salam
Hossam Alzomor
www()i-g()org

cortex m3 comparation

How to compare?
You make a list / spreadsheet
First you put in the "must have"
Then you put in other features and give them a priority, like highest priority 10 points, lowest 1 point.
Now you eliminate the devices that fail any "must have" feature. Next you add up the points according to your priority list. If the end result is a device you don't won't to use, something in your priority list is missing or needs to be reassigned.
After 2-3 alterations / loops you will be very close to the device you really want.

hth. Bob