topic Re: i.MX28 DC-DC clock domain in i.MX Processors

i.MX28 DC-DC clock domain

lategoodbye — Sun, 19 Apr 2015 10:19:59 GMT

Hi,

looking at the reference manual for the i.MX28 (Figure 10-1. Logical Diagram of Clock Domains, Chapter 10 Clock Generation and Control (CLKCTRL), i.MX28 Applications Processor Reference Manual, Rev. 2, 08/2013) doesn't show the clock domain for the DC-DC.

So i created a little ASCII art accordingly to the diagramm in the RM:

https://gist.github.com/lategoodbye/e59dbe134f74e49c4b52

Is it correct?

Thanks Stefan

Re: i.MX28 DC-DC clock domain

Yuri — Mon, 20 Apr 2015 06:09:48 GMT

Generally Your figure is correct. Note : there is no option of DC_HALFCLK in HW_POWER_MINPWR.

From section 11.2.1.2 (DC-DC Extended Battery Life Features) of the i.MX28 Reference Manual :

"DC-DC Switching Frequency—The standard DC-DC switching frequency is 1.5
MHz, which provides a good mix of efficiency and power output. The frequency can
be reduced to 750 KHz to reduce operating current in some light load situations
through DC_HALFCLK in HW_POWER_MINPWR. The DC-DC converter can
also be programmed to a frequency that is based on PLL using the SEL_PLLCLK
and FREQSEL fields in the HW_POWER_MISC register."

Have a great day,
Yuri

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Re: i.MX28 DC-DC clock domain

lategoodbye — Mon, 20 Apr 2015 09:16:15 GMT

Thanks Yuri