On Dienstag, 13. März 2018 01:32:24 CET Tomas Vanek via OpenOCD-devel wrote: > On 12.03.2018 21:53, Christopher Head wrote: > > On March 10, 2018 11:25:15 PM PST, Tomas Vanek via OpenOCD-devel <openocd- de...@lists.sourceforge.net> wrote: > I got much worse results with DAP WAIT on a slow old Intel Atom single > core industrial PC: > speed as slow as 3.618 KiB/s (without wait 48.723 KiB/s).
Just a general remark on WAIT with cheap USB shift register drivers: Even with a proper implementation of WAIT handling so that it is not treated as an error any more, the performance will be abysmal. Especially for large block writes, once you hit a WAIT condition, all following writes will be discarded, but since we do only check the result at the end of a block to save time on the fast path, a lot of discarded writes have to be replayed slowly and synchronously and that will take a lot of time. You will always have the best performance if you carefully tweak your write speed so that you reach optimum performance without ever producing a WAIT response. HLA adapters or CMSIS-DAP with SWD have a clear advantage here, because they can do a proper synchronous WAIT at the JTAG or SWD link layer and not up in the ADI protocol. BR, Matthias -- Mit freundlichen Grüßen/Best regards, Matthias Welwarsky Project Engineer SYSGO AG Office Mainz Am Pfaffenstein 14 / D-55270 Klein-Winternheim / Germany Phone: +49-6136-9948-0 / Fax: +49-6136-9948-10 VoIP: SIP:m...@sysgo.com E-mail: matthias.welwar...@sysgo.com / Web: http://www.sysgo.com _________________________________________________________________________________ Web: https://www.sysgo.com Blog: https://www.sysgo.com/blog Events: https://www.sysgo.com/events Newsletter: https://www.sysgo.com/newsletter _________________________________________________________________________________ Handelsregister/Commercial Registry: HRB Mainz 90 HRB 8066 Vorstand/Executive Board: Etienne Butery (CEO), Kai Sablotny (COO) Aufsichtsratsvorsitzender/Supervisory Board Chairman: Marc Darmon USt-Id-Nr./VAT-Id-No.: DE 149062328 ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ OpenOCD-devel mailing list OpenOCD-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/openocd-devel
