Hi Brandon. As far as I understand JTAG, OpenOCD should pull ~RESET low, and let it stay low while doing JTAG. Otherwise your microcontroller (if it's a microcontroller) would start executing the code, right ?
Your FTDI adapter, is this one you are designing/building or is it a known adapter ? If you're having problems, please make sure your pull-up/pull-down resistors are correctly connected, AND especially check the ~RESET circuit on your board. That means: Usually you connect the ~RESET on your microcontroller via a 4K7 (up to 10K) pull-up to 3V3. You connect a 100nF capacitor from ~RESET to 0V. You connect your JTAG's nSRST directly to ~RESET. Optionally connect a push-switch between ~RESET and 0V. ...But you are having problems, please let us know what you are trying to do. My guess is that you are trying to flash <some> microcontroller using OpenOCD and <a JTAG adapter you built> and it fails with <some> error. Please also let us see what kind of error is reported by OpenOCD. If your adapter is a known adapter, it will be *very* helpful to let us know which one. Please also let us know the name of the microcontroller / device / board you're trying to communicate with. Love Jens On Fri, 8 Nov 2013 16:04:41 -0500, Brandon Warhurst wrote: > I forgot to mention the following: > 1) I tried changing the ftdi_layout_init to 0x0008 0x006B. This > produces the result I was originally expecting, however, the delay > doesn't seem to have any effect. > > On Nov 8, 2013, at 4:00 PM, Brandon Warhurst wrote: > >> I was checking my FTDI adapter reset lines, and found out that they >> don't seem to toggle properly. My JTAG adapter can really only >> push-pull the reset lines, so I set both resets up as push-pull >> types (I don't have any >> output enables on the lines). The adapter is wired so that I have >> the GPIOxL lines (1,2,3, 0 is rtck) available to become a reset. >> Currently I have selected lines 1 & 2, so I've used the following >> lines: >> >> ftdi_layout_init 0x0068 0x006B >> ftdi_layout_signal nTRST -ndata 0x0020 >> ftdi_layout_signal nSRST -ndata 0x0040 >> >> This is after fooling around with the lines for a while and >> producing no results at all, meaning, on a scope, all I would see is >> the lines being driven high. When I turned on debug, I only ever >> see reset getting called once, with arguments of 0,0 for ntrst and >> nsrst. I would have expected that reset would get called again >> after delaying for "width" milliseconds to change the reset line >> state (i.e. I would expect the line to start high, given my init >> parameters, then go low during the reset period, then be pulled high >> again after the reset period). Is this not what is supposed to >> happen? I am probably misunderstanding how OpenOCD reset is >> supposed to work, but that is certainly the result I would like to >> produce. > > > ------------------------------------------------------------------------------ > November Webinars for C, C++, Fortran Developers > Accelerate application performance with scalable programming models. Explore > techniques for threading, error checking, porting, and tuning. Get the most > from the latest Intel processors and coprocessors. See abstracts and > register > http://pubads.g.doubleclick.net/gampad/clk?id=60136231&iu=/4140/ostg.clktrk > _______________________________________________ > OpenOCD-devel mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/openocd-devel ------------------------------------------------------------------------------ November Webinars for C, C++, Fortran Developers Accelerate application performance with scalable programming models. Explore techniques for threading, error checking, porting, and tuning. Get the most from the latest Intel processors and coprocessors. See abstracts and register http://pubads.g.doubleclick.net/gampad/clk?id=60136231&iu=/4140/ostg.clktrk _______________________________________________ OpenOCD-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/openocd-devel
