Benchmark: UC3 startup time

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#1
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I am working on a low power design and did some test with the EVK1100 kit. Here are some results:

Kit switched on, init GPIO (light a LED): 1 ms
Kit on, init osc0 at 12 MHz, then GPIO: 2 ms
Kit on, init osc0, init PLL0 to 48 MHz then GPIO: 2.5 ms

This was actually better than expected, especially regarding the PLL setup. The test program is written in assembly.

Wakeup from sleep:
48 MHz, time to wakeup from static sleep by NMI external interrupt: 400 us

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Is this one device, or multiple? I would check devices over different LOTs to be sure about the analog varieties in oscillators and PLLs. Anyway, nice startup times :) I guess you have a slight delay in buck-boosts starting as well, probably negligible?

Hans-Christian

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Just one kit. I wanted to find what "order of magnitude" milliseconds, and it was a positive surprise. Actually an sigma-delta ADC I'm planning to use takes much longer to start...

Sure, the power supply may take some time in addition to the MCU. Also i used filter at the wake pin, may be some integration time there too.

Edit:

Time between external power (12v at the EVK1100) stable and 3v3 stable at the board: 100 µs

I repeated the power on test by sampling the external power in stead of the 3v3 at the board and it gave similar results. The OSC, PLL and GPIO init still takes just about 2.5 ms.

I also tested the wake up time without using filter at the NMI pin and there was no difference.