Common clock and dvfs

Colin Cross ccross at
Fri Apr 22 17:18:06 EDT 2011

On Fri, Apr 22, 2011 at 1:35 PM, Mark Brown
<broonie at> wrote:
> On Fri, Apr 22, 2011 at 12:48:37PM -0700, Colin Cross wrote:
>> On Fri, Apr 22, 2011 at 12:40 PM, Mark Brown
>> > This sounds like it assumes a 1:1 mapping between clocks and supplies
>> > which is going to break at some point. ?It should be handlable but will
>> > add complexity.
>> Almost every platform requires a many-to-one mapping between clocks
>> and supplies (many clocks fed off one supply), and I bet at least one
>> platform has one clock that requires changing two supplies, so a
> In most of the platforms I've looked at the supported configurations are
> specified en masse as operating points so it definitely ends up being
> the case, you get a set of frequencies and a set of voltages specified
> as a block.

I see.  Do you happen to know if there are any max voltage
requirements for clocks?  Would running one clock in a group at a low
operating point and another at a high operating point cause a problem,
assuming the voltage is set to what is required by the high operating

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