[U-Boot] [PATCH 4/4 v4] Preventing needless switching on and off PLL bypass mode, allowing allow single-stepping through the SPL

[Robert Deliën]

> And by running off XTAL, the consumption grows so dramatically?

No, switching on the PLL does.

And the PLL can use either the external XTAL or the internal ring-
oscillator as a reference. The external XTAL is very accurate, but
uses power. The ring-oscillator is not very accurate, but very
energy efficient.

On the EVK, the external XTAL cannot be powered down
separately, so if it's consuming power anyway, there\s not reason
not to use it over the ring-oscillator. But a more generic design
may want use ring-oscillator initially.