Re: MTIME update frequency


Ved Shanbhogue
 

On Fri, Nov 12, 2021 at 05:41:02PM -0800, Greg Favor wrote:
On Fri, Nov 12, 2021 at 5:09 PM Heinrich Schuchardt <xypron.glpk@...>
wrote:

"The ACLINT MTIME update frequency (i.e. hardware clock) must be between
10 MHz and 100 MHz, and updates must be strictly monotonic."
The resolution of the mtime register is defined as 10 ns. The 100 MHz
value is irrelevant and should be deleted from the spec.
The intent of the wording is that the resolution is 10ns (as implied by the
max update frequency of 100 MHz). But I agree that the current wording
should change to just directly state a 10ns resolution.
But why mandate that it cannot be finer resolytion than 10ns. I can see a requirement to say minimum of 10ns but whats the rationalet to say must not be better than 10ns?

regards
ved

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