Duane Ellis <open...@duaneellis.com> wrote on 2009-09-07 21:29:50: > Jonas Horberg wrote: > > Note that configuration files with jtag_khz or jtag_rclk can not be > > used with the parport interfaces until a fix is created. > > > Huh? Sorry I'm late to this thread but I have a question.
jtag_khz and jtag_rclk require that the interface driver has the khz and the speed_div functions. The parport driver currently lacks them. > The idea here is: "jtag_khz 1000" - should mean no faster then 1mhz > There is no "min-freq" requirement, and to do so would be wrong. Correct. > Or am I missing something, ie: we *MUST* have a minimum frequency. No, there is no requirement for a minimum frequency setting. I am not sure what made you think that I required this. Perhaps this: > Jonas Horberg wrote: > I think that the scheduler, but also the interrupt handling to a > lesser degree, will have a too large effect on the timing. > Remember, we actually want to set the minimum time that elapse > between TCK transitions. We will only get an average value and > it is impossible to extract the shortest time from it. We have to > put in a large safety margin and the speed will in most cases be > much lower than requested. (timing in the first sentence refers to the automatic parport toggle speed detection) The problem with a speed much lower than the requested is that it hurt the performance badly. The parport interfaces will operate at a much lower speed than they are capable of and the user will not be aware of this. Best regards Jonas _______________________________________________ Openocd-development mailing list Openocd-development@lists.berlios.de https://lists.berlios.de/mailman/listinfo/openocd-development
