Michael, Thanks!! At least you have confirmed 3us, so my guess of 7us for an average amforth word is not so bad (:-)). I am using rtc as well, however for these time measurements I use ticker (you may see it somewhere in the post). I am thinking now to use 16bit counter for the hw timer1 clocked by f_cpu and I will read its value as well the info from timer variable (incremented by timer1 overflow). So I may get sub usec resoulution. However, the ticker will make the measured time longer by ticker handling, you are right. I am using 30000 do-loop for those measurements so it is ok, I guess. The resolution of my timer is 10ms (one shot). But there is other Q I would like address - how to measure a word duration? Imagine to measure f/. So the loop might be:
30000 0 do _pi _pi f/ fdrop loop .... or 30000 0 _pi _pi do fdup fdup f/ fdrop loop ... the empty loop: 30000 0 _pi _pi do fdup fdup fdrop fdrop loop ... or 30000 0 _pi _pi do loop... Which one. So to measure you need to know the duration of other words as well.. Simply how to isolate f/ as much as possible? The other possibility is to fill the f/ and empty it directly in asm,, or simply run everything in simulator. I've measured the f/ (735 cycles) and f* (190) in simulator with real data, but not keen do it with every word (:-))). Pito > So I have 3 / 0.05 = 60 cycles for 'one word'. > > So where does amforth spend 24 more cycles? That > is at an average the > overhead caused by my ISR time ticker of RTC, I > guess. > > To see a word "as is" connect an oscilloscope to a > port pin. let an > empty loop toggle your port pin. Than add your > word to the loop an > run again. > In the resulting frequency difference you get the > execution time of > your word. > > Michael > > > > > > > > > > ------------------------------------------------------------------------------ > > Start uncovering the many advantages of virtual > appliances > and start using them to simplify application > deployment and > accelerate your shift to cloud computing. > http://p.sf.net/sfu/novell-sfdev2dev > _______________________________________________ > Amforth-devel mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/amforth-devel ------------------------------------------------------------------------------ Start uncovering the many advantages of virtual appliances and start using them to simplify application deployment and accelerate your shift to cloud computing. http://p.sf.net/sfu/novell-sfdev2dev _______________________________________________ Amforth-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/amforth-devel
