Hi Oleg et all, On 12/9/19 9:25 PM, Oleg Hahm wrote: > I think the problem statement and the requirements could indeed be more > precise - while I must admit that a lack of precise requirements is a failure > of the RIOT community.
Yes, that could be. I intentionally did not add requirements. I just added a clarification on "adaptable to varying configurations of timers, RTTs, RTCs (use RTC if available for super-long-time timers)", trying to convey later on that xtimer just doesn't fulfill this requirement, and "fixing" that involves changing most of it. > Anyway, I think we need to define what "very efficient timers for use in > time-critical drivers" means in order to being able to check whether the > proposal fulfills the requirement or not. We can try. What would that look like? Something like "must not incur more than x us overhead on hardware of class y"? > Besides I'm missing a requirement regarding the maximum granularity and the > maximum duration of a timer. You mean minimum granularity? Anyway, good point. xtimer has 64bit range with 1us precision. ztimer makes the trade-off of only offering 32bit range, but with flexible precision. I'm not sure we can get away with that, if just for the fact that we have code using the 64bit functions, which means automatic code conversion using coccinelle is not (easily) possible. I think I'll just implement a 64bit version (as an extra module) so a possible transition gets easier. And to checkbox "any precision possible (if hardware keeps up), 64bit range supported". Kaspar _______________________________________________ devel mailing list devel@riot-os.org https://lists.riot-os.org/mailman/listinfo/devel
