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Re: Energy consumption of XL216-series

Posted: Fri Feb 10, 2017 11:45 am
by henk
Hi Chris,

Yes - you should set the clock speed of the switch lower - it will help.
Transfer rate through the switch is linear in the clock speed.
The tile-to-tile limit is ClockSpeed x 4 bytes per second.

So the default speed is 500 x 4 = 2 Gbytes per second. Not many applications need that, and you can for example reduce it by a factor of 10 to 200 Mbytes per second, and reduce the power consumption significantly. Alternatively, you can speed the clock up when you need it and slow it down a factor 100 when you don't need it.

This is only for tile-to-tile communication; it does not affect communication between "logical" cores.

Cheers,
Henk

Re: Energy consumption of XL216-series

Posted: Thu Feb 16, 2017 3:50 pm
by ChrisDev
Hi,

as mentioned before by henk, a good option to save energy is to shut down the processor if there will be some idle time.

Now I'm curious if the boot or rather start-up time the processor needs is logged in any register. It would be nice if we could determine dynamically how long the last start up sequence took and if it's worth it to shut down again or if the time slot will be too short.

wbr,
Chris

Re: Energy consumption of XL216-series

Posted: Thu Feb 16, 2017 4:02 pm
by henk
I am afraid it isn't logged as such. But - it is completely predictable. Set a wire high online one of your code, and measure the time between RST_N going high and that pin going high. You will need an oscilloscope to measure that (or another xCORE).

There are some options to speed up the boot process; including using a faster QSPI clock.